Zombra said:
My ideal shooter will be often stressful but rarely frantic, with a confident, measured pace, plenty of quiet moments, and excellent audio/visual feedback from the combat, like solid booms from the guns and the satisfying ping of an ejected clip. You know what I'm talking about.
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Edit: additional notes: In general, I don't have the patience to explore and work with mods. If the game isn't good vanilla it will have a significantly reduced chance I will want to play it.
Also I am not especially looking for an "old school" shooter experience, games do not get bonus points for being old. Between a good new game and a good old game, I would probably rather try something newer first.
Given the conditions you set, I suppose old school shooters don't often involve very diversified pacing, the way more tightly-scripted shooters later on did, but I would still recommend giving them a serious try because, contrary to the appearances, the way they flow is very good and doesn't get tiresome. That being said, here's a list of what I've played and liked; the selection is not nostalgia-driven as I got into all those older titles only in the last several years. I've included only the titles which I did not see on your list.
I'll place an asterisk before strong recommendations.
* Doom (Ultimate Doom) – I really feel that this is the best FPS ever: satisfying weapons, excellent flow and rhythm to the combat, good level design, great music; I think the new release by Bethesda includes SC-55 MIDI recordings, which removes the need for other source ports;
Doom II – adds a few new elements, but it's more like an expansion than an entirely new game; it mainly focuses on more tricky level design;
John Romero's ‘Tech Gone Bad’ and ‘Phobos Mission Control’ maps released in 2016 are very good, and then his more recent stand-alone episode for Doom called Sigil (use the software renderer in the source port when playing these, otherwise the lighting will look completely wrong);
Star Wars: Dark Forces – good atmosphere, faithful to the old films, very nice level design, and the combat is reasonably satisfying, if rather simplistic; SC VA can supply adequate rendition of the MIDI music;
Star Wars Jedi Knight: Dark Forces II – the combat stays fairly simple, with the addition of light sabre duels, and the level design continues to be very expansive and offer fun exploration; there is a problem with the way music tracks are played on modern systems, even in the GOG and Steam releases, so this needs to be looked into before playing;
Star Wars Jedi Knight: Mysteries of the Sith – more of the above, with a somewhat questionable finale;
* Quake – Id's second masterpiece: great flow, combat, monsters, weapons, level design, music, and atmosphere;
Quake II – enjoyable enough for what it is, despite being quite unlike the first instalment and the combat being too easy; Id's touch is still evident in the overall quality;
Turok: Dinosaur Hunter – a simple shooter originally made for Nintendo 64; its main point of interest is the steady running pace the player is encouraged to maintain throughout; warning: Night Dive's more recent release has reduced level complexity;
* Shadow Warrior (1997) – a
de facto successor to Duke Nukem 3D, since it's based on the same engine and made by the same people; enjoyable but trickier combat, nice atmosphere, and again an enjoyable sense of humour;
Shadow Warrior: Wanton Destruction – a fun expansion pack with nice levels;
* Blood – also made on Duke's engine and following a similar formula with enjoyable twists; nice style and again a memorable protagonist; developed by Monolith which went on to make F.E.A.R.; Blood: Fresh Supply by Night Dive does not change the contents of the game;
* Unreal – it starts out rather slow and unimpressive in terms of combat, but the enemies become more challenging later and the arsenal the player is given includes some all-time classics like the flak cannon; the level design is quite impressive and the visuals look excellent to this day, just remember that there's a certain setting that must be disabled, which I wrote about in response to Lady Error;
Unreal Tournament 2004 – the single-player campaign is not as good as in the first one, but it's still enjoyable enough (except for some modes) to check it out;
* Sin – another one of the greats, with more emphasis on set pieces in a manner not too different from Half-Life; the characters and progression through very diverse locations adds a lot to the sense of it being like a comic book or a silly action film;
Half-Life: Uplink – an extra chapter for the first game released as a demo or a bonus with some cards; well worth playing;
Kingpin: Life of Crime – a very uneven game, as it loses most of its positive qualities after the first hub, but the way it starts is interesting enough to warrant a mention;
Medal of Honor (1999) – a console shooter, but the audio-visual aspects and even the way the weapons handle feel surprisingly good even today; good atmosphere;
Medal of Honor: Underground – similar to the above, though somehow a little less enjoyable;
* Serious Sam: The First Encounter – a seriously enjoyable series; the first game starts out a little unassumingly; it's better to play the non-HD version first because some of the special engine features that involved gravity manipulation were not included in the new engine, so areas that relied on those were cut or simplified; it also seems like the original version is a bit more challenging;
* Serious Sam: The Second Encounter – same formula as above, but the level design and encounters tend to involve some serious twists; again the non-HD version is seriously superior, among other reasons because certain seriously impressive effects did not make it into the final level (and I played the original version after the HD one);
Serious Sam 2 – though it was seriously casualized to adapt it to the console market, it's still somehow enjoyable for what it is;
Serious Sam HD, the first and second Encounters are different enough visually to warrant playing them separately at some later date;
* Serious Sam 3: BFE – the level and encounter design are uneven, but it can be fairly challenging and includes some serious battles;
Postal 2 – the game design in this is kind of amateur and it can get downright stupid, but the game undeniable has a rather special personality of its own; it has rather creative weapons; in the new version it's better to select the base game's campaign separate from the expansion as otherwise all the new weapons are available from the beginning, throwing off the balance too much;
Postal 2: Apocalypse Weekend – the production quality gets worse, but somehow it manages to entertain;
Postal 2: Paradise Lost – a bit better, worth it if one enjoyed the base game;
Call of Duty – before it became one of the great heralds of decline, it was simply an enjoyable, atmospheric cinematic shooter; worth playing once;
Call of Duty: United Offensive – more of the above;
Call of Duty 2 – it was turned into a rather dumb single-player death match with bots masquerading as Second World War, but it was still kind of enjoyable;
* Painkiller – a very straightforward ‘hordes of monsters come at you and you blast them away’ game, but it's exceedingly good at it; it's the real origin (or else the first case) of what passes for the contemporary idea of ‘old school shooters’; play the original, not the Hell & Damnation remake which cuts out a lot of content and takes other liberties with the game; the latter might warrant playing separately later for the changes in the visuals and perhaps some new levels?
Painkiller: Battle Out of Hell – a pretty good expansion pack;
* The Chronicles of Riddick: Escape from Butcher Bay – a rather unique hybrid shooter, first-person fisticuff, and stealth game with a main character who has a very well realized presence in the game; much better than the film it was supposed to accompany (although Pitch Black that came prior to both was enjoyable); avoid the remake that comes with the expansion Assault on Dark Athena, it simplifies some sections in a bad way and perhaps also cuts some content (but I can't recall the details), but on the other hand, it has some visual improvements;
Brothers in Arms: Road to Hill 30 – it's a shooter designed for Xbox, so it's rather static, but as it was mentioned, it does have an unusual squad-commanding feature and the weapons do feel rather good;
Afraid of Monsters: Director's Cut – a nice horror modification for Half-Life with rather interesting weapons handling;
F.E.A.R.: Extraction Point – I didn't see it on your list, it's worth playing;
* S.T.A.L.K.E.R. (it seems that the original Ukrainian and Russian release possibly didn't have a subtitle—could any one confirm?) – it had a troubled development and the uneven approach to area and quest design bears this out, but it's a very unique and memorable game; the early weapons feel rather weak due to idiotic progression system, but the better ones later on are very enjoyable to use;
S.T.A.L.K.E.R.: Clear Sky – largely a rehash of content from the base game with some more poorly executed ideas, but it's worth it, should you find the first one enjoyable;
S.T.A.L.K.E.R.: Call of Pripyat – it realizes the original vision somewhat better, but the visuals, music, and atmosphere suffered due to the departure of some of the original team members;
Wolfenstein (2009) – one of those games one would expect to be a case of ‘design by a committee’, but it's unexpectedly enjoyable;
Metro 2033 – atmospheric, beautiful visuals, very good-feeling weapons; the game design is rather linear, at times restrictively scripted, and it unnecessarily tries to go for a cinematic style, but those things don't detract from its positive qualities too much; the Redux version is questionable: the stealth was rather poorly implemented before, but in the remake it's laughably easy; some graphical changes weren't for the better either, despite the technically superior version of the engine;
Metro: Last Light – the cinematic, scripted tendencies get worse in some parts and the plot is rather silly, but it's still an enjoyable shooter;
Cry of Fear – from the author of Afraid of Monsters, again a modification for Half-Life, this time quite elaborate and very serious about giving the standard FPS gameplay a ‘survival horror’ feeling;
* Dusk – very enjoyable, gets better in the second episode;
Ion Maiden – a retro shooter made using Duke 3D's engine; despite some criticisms, I'd say it gets fairly good later on; I think the main problem with the game is that the team was so in love with the idea of the visually-impressive cyberpunk city that they sacrificed the gameplay early on; the later chapters have level design that feels better with the game's enemies and encounter design.