Over at gamefaqs, users can rank a game's difficulty with a 1-5 scale and they've also set it up that you can list 'em by rank as so
https://gamefaqs.gamespot.com/games/rankings?platform=19&genre=48&list_type=diff&dlc=1&min_votes=2. I've cherry picked a bunch of notable titles so youse don't have to sift through all the shovelware. The first number is the quality ranking (out of 5), the second is the difficulty score, 5 being the highest quality/difficulty.
Wizardry: The Return of Werdna - The Fourth Scenario 3.64 4.55
Might and Magic: Book One 3.38 4.39
Buck Rogers: Countdown to Doomsday 3.97 4.33
Wizardry V: Heart of the Maelstrom 4.00 4.17
Wizardry VI: Bane of the Cosmic Forge 4.10 4.13
Wizardry: Proving Grounds of the Mad Overlord 4.13 4.13
Buck Rogers: Matrix Cubed 4.25 4.13
Wizardry VII: Crusaders of the Dark Savant 3.95 4.10
An Elder Scrolls Legend: Battlespire 3.04 4.06
Serpent in the Staglands 3.89 3.93
Gateway to the Savage Frontier 3.68 3.92
Ultima III: Exodus 3.26 3.90
Darklands 4.17 3.89
Geneforge 5: Overthrow 3.82 3.89
Dungeon Master 3.92 3.88
Wasteland 4.09 3.88
The Bard's Tale: Tales of the Unknown, Volume I 4.09 3.86
Realms of Arkania: Star Trail 3.82 3.86
Might and Magic II 3.56 3.83
The Age of Decadence 3.62 3.83
Underrail 4.12 3.82
Wizardry 8 4.26 3.82
The Dark Queen of Krynn 3.35 3.80
Death Knights of Krynn 3.90 3.80
Gothic II: Night of the Raven 4.34 3.79
Elex 3.29 3.77
Dungeon Master II: The Legend of Skullkeep 3.74 3.75
Champions of Krynn 3.63 3.73
The Bard's Tale II: The Destiny Knight 3.80 3.73
Ultima V: Warriors of Destiny 4.05 3.72
Pathfinder: Kingmaker 4.23 3.71
Pools of Darkness 3.72 3.70
Avernum 5 3.40 3.70
Divinity: Original Sin Enhanced Edition 4.23 3.69
Realms of Arkania: Blade of Destiny 3.60 3.69
Ultima II: The Revenge of the Enchantress 2.68 3.68
Ultima IV: Quest of the Avatar 3.89 3.67
Realms of Arkania III: Shadows Over Riva 3.98 3.67
Divinity: Original Sin II 4.31 3.64
Avernum: Escape From the Pit 3.75 3.64
Eye of the Beholder II: The Legend of Darkmoon 3.85 3.63
Icewind Dale II 3.95 3.60
Baldur's Gate 4.24 3.58
Avernum 6 3.52 3.58
Pool of Radiance 3.95 3.56
Eye of the Beholder III: Assault on Myth Drannor 3.19 3.56
The Witcher 2: Assassins of Kings 4.12 3.52
Baldur's Gate II: Throne of Bhaal 4.38 3.51
Curse of the Azure Bonds 3.84 3.50
The Bard's Tale 3: The Thief of Fate 3.42 3.50
Geneforge 4: Rebellion 4.14 3.50
Eye of the Beholder 3.74 3.48
Avernum 4 3.45 3.46
Geneforge 3 3.65 3.44
Might and Magic III: Isles of Terra 4.09 3.44
Fallout: New Vegas - Dead Money 3.59 3.44
Secret of the Silver Blades 3.90 3.43
Pillars of Eternity: The White March - Part 1 3.83 3.43
Gothic II 4.20 3.42
Fallout 2 4.34 3.42
Baldur's Gate: Tales of the Sword Coast 4.11 3.41
Baldur's Gate II: Shadows of Amn 4.46 3.40
Fallout 4.14 3.40
Divinity: Original Sin II - Definitive Edition 4.00 3.40
Ultima VII: The Black Gate 4.36 3.38
The Temple of Elemental Evil 3.55 3.37
Divinity: Original Sin 4.14 3.37
Might and Magic V: Darkside of Xeen 4.16 3.34
Wasteland 2: Director's Cut 3.73 3.34
Avernum 2: Crystal Souls 3.76 3.33
Pillars of Eternity: The White March - Part 2 3.62 3.33
Ultima VI: The False Prophet 4.02 3.33
Mount & Blade: Warband 4.20 3.32
The Elder Scrolls III: Morrowind - Game of the Year Edition 4.34 3.31
The Elder Scrolls III: Bloodmoon 4.08 3.31
Icewind Dale 3.93 3.30
Mount & Blade 3.87 3.30
Icewind Dale: Heart of Winter 3.89 3.30
Ultima VII Part Two: Serpent Isle - The Silver Seed 4.12 3.29
Neverwinter Nights 2: Mask of The Betrayer 4.14 3.29
Arx Fatalis 3.73 3.29
Pillars of Eternity 4.05 3.29
Risen 3.69 3.29
Might and Magic VI: The Mandate of Heaven 4.25 3.28
Dragon Age: Origins 4.30 3.26
Ultima VII Part Two: Serpent Isle 4.30 3.26
The Elder Scrolls III: Morrowind 4.29 3.25
The Elder Scrolls III: Tribunal 4.01 3.24
Shadowrun: Dragonfall 4.08 3.23
Arcanum: Of Steamworks and Magick Obscura 4.23 3.21
Ultima Underworld: The Stygian Abyss 4.08 3.20
Torment: Tides of Numenera 3.65 3.18
Planescape: Torment 4.47 3.18
Fallout: New Vegas - Lonesome Road 3.89 3.17
Neverwinter Nights: Kingmaker 3.68 3.17
Treasures of the Savage Frontier 3.73 3.17
Wasteland 2 3.94 3.17
Might and Magic VII: For Blood and Honor 4.31 3.15
Shadowrun: Dragonfall - Director's Cut 4.13 3.14
The Witcher 3.91 3.14
The Witcher 3: Wild Hunt - Hearts of Stone 4.38 3.13
The Witcher 3: Wild Hunt - Blood and Wine 4.41 3.12
Avadon: The Black Fortress 3.49 3.12
Fallout: New Vegas - Old World Blues 4.07 3.12
Avadon 2: The Corruption 3.78 3.12
Ultima I 3.06 3.12
Neverwinter Nights 2 3.86 3.11
Neverwinter Nights: Hordes of the Underdark 4.13 3.10
Neverwinter Nights 4.00 3.10
Neverwinter Nights 2: Storm of Zehir 3.58 3.10
Ultima Underworld II: Labyrinth Of Worlds 4.25 3.10
The Witcher 3: Wild Hunt 4.54 3.09
Vampire: The Masquerade - Bloodlines 4.24 3.09
Risen 3: Titan Lords 3.34 3.07
Neverwinter Nights 2: Mysteries of Westgate 3.61 3.06
Dragon Age: Origins - Awakening 3.94 3.05
Risen 2: Dark Waters 3.50 3.05
Dark Sun: Shattered Lands 4.03 3.04
Fallout: New Vegas 4.24 3.04
Gothic 3 3.49 3.03
Fallout: New Vegas - Ultimate Edition 4.38 3.03
Tyranny 3.89 3.03
Neverwinter Nights: Shadows of Undrentide 3.84 3.02
Star Wars: Knights of the Old Republic 4.37 3.02
The Elder Scrolls IV: Shivering Isles 4.22 2.99
The Elder Scrolls IV: Oblivion - Game of the Year Edition 4.29 2.99
Star Wars: Knights of the Old Republic II - The Sith Lords 4.16 2.97
Dungeon Siege II 3.75 2.97
The Elder Scrolls IV: Oblivion 4.20 2.96
Dungeon Siege 3.63 2.96
Fallout 3: Game of the Year Edition 4.17 2.95
Mass Effect 4.14 2.95
Baldur's Gate: Siege of Dragonspear 3.21 2.93
Alpha Protocol 3.62 2.93
Fallout 3 4.07 2.92
Shadowrun Returns 3.66 2.91
The Elder Scrolls V: Skyrim - Dragonborn 4.11 2.91
Fallout 4: Game of the Year Edition 3.90 2.90
Dragon Age: Inquisition 3.88 2.89
The Elder Scrolls V: Skyrim 4.32 2.88
The Elder Scrolls V: Skyrim - Dawnguard 4.13 2.88
Dragon Age II: Legacy 3.55 2.88
The Elder Scrolls IV: Knights of the Nine 3.86 2.84
Dragon Age II: Mark of the Assassin 3.64 2.81
Shadowrun: Hong Kong 3.97 2.80
Fallout 4 3.71 2.78
Fallout: New Vegas - Honest Hearts 3.72 2.76
Pillars of Eternity II: Deadfire 3.91 2.74
Dragon Age II 3.37 2.71
Arcania: Gothic 4 2.74 2.36
Fallout 76 1.88 1.96
While I don't agree with all the individual placements, I do believe they got them all in the right ballpark. Congratulations to Sawyer for delivering a Dungeon Siege-tier screen saver with Deadfire, truly a pathetic job.