RetroGaming

Yoshis island
Super mario world
DKC 1, 2 & 3 Pokemon gen 1&2
Banjo kazooie & tooiee TLoZ A link to the Past, Ocarina of time & Majoras mask
Warcraft 3 + frozen throne
Command & conquer 2 + yuris revenge

I've still got my Nintendo 64, and I sometimes boot up Goldeneye for old time's sake.

Half-Life 1 (and expansions)

SimCity 3000, SimCity 4

Vampire the Masquerade: Bloodlines

Deus Ex

Zoo Tycoon

Leisure Suit Larry 7: Love for Sail

Morrowind

Industry Giant 2

Fallout 1/2

Arcanum

SimTower

I still love all of the 90s FPS games like Doom and Quake.

Half-Life 1

One mod specifically (Sven-Coop). Been playing almost daily since 1999.

I still fire up Duke 3d and Quake mods from time to time as well. There are lifetimes of user-made content in some of these older games.

I still play through The Legend of Zelda: A Link to the Past at least a couple times a year though it's usually with the randomizer these days. It is objectively the best video game ever made, which helps.

Guild wars 1. I don't play it often but every once in a while I get the itch. It's honestly still really compelling.

I'll still crack open any one of the Age of Empires series from time to time.

Final Fantasy 6 but, back in my day, it was called Final Fantasy 3.

Tales of Maj'Eyal; all the old scumm games, daggerfall, toejam & earl.

The Pokemon games on all of Nintendo's handheld consoles emulate really cleanly on a smartphone.

I'm a sucker for the Gen 1 nostalgia every now and then.

DOOM.
The old game got way better when they open sourced it and Quake 3d code was backported to make zDOOM. Its one of the largest modding communities that has ever existed. If you want to see what it can do, try Brutal Doom. That same engine is behind a new release called Selaco.

Serious Sam.
The first one. The demo is fine. Start off with a pistol. Its pretty easy to die at first, even if you know the game. I think that's why I keep opening it, I know it really well, and it still catches me.

Quake. Still hold up, modding community makes tons of maps to play so it stays fresh.

Dungeon Keeper - keeperfx is a modern update of the engine / bug fix that makes it easy to play on a modern system.

Here goes:

pc:

• duke nukem 3d pc version
• blood
• redneck rampage (so funny!)
• cannon fodder
• day of the tentacle

megadrive:

• streets of rage 2
• road rash 2
• ea hockey 2

Master of Orion.

I sunk hours into NetHack, and I still occasionally dive into the dungeons. I also have a NES emulator on my phone, but it's just not the same. I'll play Zelda or Metroid for the nostalgia, but it's not the same as sitting on the couch with friends.

Super Nintendo:

• Megaman X. I was never a fan of classic Megaman, but the faster, more action-oriented sequel/spinoff X series rates amongst my favorites. It has tight controls, good music, varied stages, and memorable bosses and combat encounters. I must have beaten the first game dozens of times over the years.
• The Legend of Zelda: A Link to the Past. It and Link's Awakening on the Game Boy were so close to perfect that decades later they're still the basis of comparison for any new 2D Zelda-like.

PC:

• Baldur's Gate II: Shadows of Amn. it was the game that introduced Bioware's trademark party banter and focus on interesting and likeable characters. The systems are a little rough but it still mostly holds up. Though it's been a while since my last playthrough, and I usually stop once I hit the Underdark and the open world structure constricts for a few hours.

Syndicate Wars. I honestly haven't seen anyone emulate that gameplay as well as SW did it since then.

If I could I'd still be playing wow but it's just not the same without the plentiful free time for it.

Heroes of Might and Magic III

Worms Armageddon

Command & Conquer: Red Alert 2

Every time Final Fantasy Tactics comes out again, I’m all over it.

Fallout 1 & 2, Final Fantasy 9, Elite

Age of Empires

I have replayed Baldur's Gate 2 more than any other narrative game, and will probably do another playthrough in the coming years. So it's most likely that. Oh, and Tenchu: Wrath of Heaven multiplayer on the PS2 whenever I am over at one specific friend's place. That was our go-to couch game growing up and it's still nostalgic.

Major mix of eras and platforms, but here is my list.

AoE2

NFSU2

Halo MCC

Sim City 2000

Streets of Sim City

Roller Coaster Tycoon

Mario Kart 64

Perfect Dark

Goldeneye

Battlefield 3

Super Mario Bros Deluxe

Mario 64

Overwatch

Half Life 2 +eps

Gary's Mod

Command and Conquer Generals: Zero Hour

Fallout New Vegas

I've been on a Doom kick for a bit, although it's modified to retain some more current gen flair. Just finished Going Down Turbo with Project Brutality. Is it faithful to the OG? Not quite, but it's truly amazing how far the the engine has come despite being heavily modified in its own right.

I didn't have video games in my youth, so I'm just catching up now.

I bloody loved Harry The Handsome Executive. It was an Ambrosia Software shareware game from the 90s and was surprisingly underrated. Will probably run on Infinite Mac but it never got an OS X port or anything

I have an old iBook which it still runs great on

Solitaire.