(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.
Mass Effect trilogy.
Or maybe Bioshock.
Either/both.
Very late edit: Deus Ex. I still play it every once in a while and while the graphics are terrible, it's a lot better with GMDX and you get used to it very quickly. That game is still a masterpiece.
I was thinking ME trilogy as well, but while ME1 is a great game it doesn't really hold up in terms of graphics today. ME2 and ME3 still look fine though.
Oh the graphics don't bother me at all, the Legndary edition holds up fine, I think. But ME1 has the best story in the trilogy, it's why I still play it. I still remember the first time I played it. Being made a Spectre, speaking to Sovereign, the attack on the Citadel. How scary and unknowable the Reapers were. Hanging up on the Council. ;) The main storyline is better than 2 and 3 combined, imo. However, you are right that ME1 has some issues. While the Legendary Edition fixed a lot of the issues (and it does play smoothly, I do think), there are some things in ME1 that have become so tedious I don't even do them anymore. Mainly talking about the exploration of unchartered worlds and the terrible handling of the Mako, or how every outpost looks the same, every mine looks the same, with the exact same layout. Makes it feel way more dated than it feels if you only go through the story. Not to mention the headache that is inventory management and swapping weapons and mods and grenades, turning everything into omni-gel because the stupid mini-game is even more annoying than inventory management!
For this reason I made a few save games that I 100%ed (one paragon, one renegade, different romances, etc). And I backed those up. Now, whenever I play ME1 I only do the main storyline and some side quests, and ignore the rest, lol. Then in ME2 I import one of the files I saved. Cut out all the tedium. ;)