Anyone who's read me whinge about Diablo 4's open world will know that, earlier this year, I played Diablo 1 for the first time. The way I did that was via DevilutionX, a fan-made source port of the original Diablo and its Hellfire expansion that lets you play the trailblazing original on modern systems with all sorts of 21st-century creature comforts like gamepad support and high framerates. When I played, it was on version 1.4, but now its recent 1.5 update (spotted by GamingOnLinux) has made it better than ever.
You can get a full run-down of everything DevilutionX 1.5 brings over on its GitHub page, but here are some highlights. First and foremost, the game's multiplayer mode will now let you complete all of Diablo's quests, you can toggle on floating damage numbers, and you can toggle coloured inventory slots based on item quality (much like pretty much any modern loot-based game).
You can also now play it on the original Xbox, in case you have that incredibly particular burning need.
I really can't praise DevilutionX enough. It played D1 like an absolute dream on my M1 MacBook Air (Whoopi Goldberg would be proud) earlier this year, and it seems like it's only getting better. The ability to set the old classic at modern resolutions and play it using modern control methods—and even on the Steam Deck—is an absolute godsend. At some point, I'll get around to playing Hellfire using it as well.
You can pick up DevilutionX over on GitHub, but remember you'll need a (legit) copy of the original game to make it work. All you have to do is download the latest version, copy over DIABDAT.MPQ from the game's install folder into the DevilutionX folder, and you're off to the races. If you want to play Hellfire, you'll have to copy hellfire.mpq, hfmonk.mpq, hfmusic.mpq, hfvoice.mpq over as well. You can find a more detailed set of installation instructions here, including how to put it on stuff like the Switch, 3DS, or your phone. God bless fans.