I'd say FF 7. Almost everything after that is pretty shit imo.
I'm not a huge fan of 7 but I wanted to go at least as far as 9, which I think is pretty good (albeit way too dialogue/cutscene heavy).
I mean... the game literally ends on a cliffhanger. So no.
I think the ending works as a self-contained story. Freeman survived the Black Mesa disaster and has been hand-picked by some weird alien/government freaks to be their new agent. He either dies in a blaze of glory against the unwinnable alien grunt battle, or is whisked off by the G-Man to an unknown future. Obviously the latter ending is huge sequel bait but it would still work as a satisfying ending even if there had never been another Half-Life game. I also like how the cosmic horror keeps scaling up throughout Half-Life, culminating with the huge fetus that shoots teleporters. You've seen something so horrific and incomprehensible that no sequel could ever really expand on it in a meaningful way - indeed, we end up with the Combine, who are a bunch of losers in gasmasks and feel like a laughable step down from whatever the hell the Nihilanth was.
Speaking of the Combine... Half-Life's ending seems to imply, however vaguely and ambiguously, that you might have saved Earth from invasion. You're either dead or trapped in nightmare-hell stasis, but at least you might have saved everyone you loved. Half-Life 2 then says "oh actually there were some clowns in gasmasks behind everything and they overran Earth about one second after you left. sorry!" What was the point of anything that happened in HL1, then?! Might as well have just died in the test chamber.
I won't retard-rate you, but it's a very odd opinion considering how good System Shock 2 is. Have you actually played it?
Not going to go too far into it here, but SS2 annoys me in a similar way to HL2. That is to say, about half of my criticisms are of the quality of the game itself, and the other half are of the game as a sequel.
Briefly, though:
- I don't like the RPG-lite elements at all and I don't understand why they're in the game. This isn't Deus Ex, it's a corridor shooter that's trying to pretend it's something else, and it gets weighed down by this kind of thing
- The enemies are almost universally boring to fight with shit AI
- Similarly, combat is completely unsatisfying, partially due to the pointless RPG/skill elements. People will argue that this is acceptable because combat isn't the main focus of the game, but I don't agree, combat and exploration are pretty clearly the core of the game
- Enemies respawning was a terrible idea. SS1 did this as well but it was much more manageable since SS1 was a dedicated shooter and you always had tons of ammo and combat was swift and brutal
- Degrading weapons. Fucking why. I get that resource scarcity is meant to be a major aspect of the game, but it doesn't work because the game still really isn't very difficult at all, so having your shit break is more of an annoyance than anything
- Beating a dead horse, but the endgame sucks more than Xen could ever dream of sucking
- This is personal taste I guess, but I didn't find the plot at all interesting. The tone didn't work for me either - SS1 was enjoyably ridiculous and very fast-paced and action-packed, whereas SS2's shift to survival horror results in it feeling like a game from a different (and worse) franchise altogether, not least because I didn't find the game effective as a horror game
- Similarly, the Von Braun and that other ship with all the weird shit on it aren't as fun to explore as Citadel Station