(Saw this question asked on another popular link aggregation website and it got me thinking)
If you could play one game for the first time all over again, what would you choose? This might be because you want to do it all again, or because you don't think you got enough out of it the first time. It could be experiencing the game exactly as you were back then, or experiencing a game with what you know now.
For me, it's Legend of Zelda: A Link To The Past, experienced exactly as I was back in 1991.
Nothing comes close to how jaw-droppingly amazed I was by that opening sequence. The epic orchestral score, the cinematic rainstorm, creeping around in the dark... it was a generational leap above anything I'd played on 8-bit computers and consoles, and even the Megadrive. I'd love to play it again without thirty plus years of Nintendo/Zelda knowledge, or without knowing about the dark world.
It's hard to pick just one:
Deus Ex. It's timelessly topical despite being released in 2000. It predicted the War on Terror and a massive pandemic to name a couple.
Spiritfarer, for maximum onion chopping. Saying goodbye to Gwen really messed me up since I became very attached to her, and I can't finish the last stretch of the game because it's too emotionally taxing.
Undertale and wholesome fan-games like Act to Flirt.
Half-Life 2, circa 2004 when it was a leap ahead of everything else. I was unsettled by the teaser screenshots due to how real it all seemed to be during its heyday. (I did re-capture part of that feeling with M Mod and its great yet faithful modernisation effects. Plus there's some blursed mods you can combine with it such as replacing Alyx with Krystal, voiced by the original actress.)
Duke Nukem 3D: Alien Armageddon. It blew me away how much custom content and passion has been invested, so good that it almost felt like I was playing Duke Nukem for the first time all over again.
There's many more worth mentioning such as Unreal, Morrowind, Oblivion, Company of Heroes 1 and the forgotten gem that is Ground Control.
Man, I was born just at the right time to experience a stunning variety of titles and enjoy the mods that improve them.
The first time my friend and I fired up Unreal we were completely blown away. The flyby camera through the castle at the menu screen was unlike anything we had seen before.
Have you checked out Unreal Tournament 99? Also has a fly-through of a building, and boy that game was awesome and still is.
Yeah, that one's great! I played a ton of it back in the day. Lots of fun was had with the ChaosUT and Unreal4Ever mods.