I'll just give a few examples:
- Banjo Kazooie (N64)
One of the all time great platformers, holds up really well, I replay it once every year since at this point it only takes me a day or two.
- Unreal Tournament 99 and 2004
While my reflexes are gone and I get absolutely stomped in those games, it's still fun to me, as I love arena shooters. If I'm in a place where my ego can't take a hit like that I'll just play against bots.
- Guild Wars 1
My first MMO. It's completely devoid of players now, but loading it up late at night every once in a while gives me a sense of serene loneliness. Like revisiting your hometown despite knowing that all your friends from back then have moved away. As the saying goes: "You can revisit the past, but noones there".
We recently bought an apartment, and I use our guestroom to keep a TV where I keep my old consoles (N64, PS2, Dreamcast and Gamecube) hooked up and it's been great replaying old favourites with pizza, beer and the best of friends.