My last console was an xbox in 2002. I had a few games and I bought into the Splinter Cell hype in 2003. I got the game, and for me the controls were not intuitive and too complex. That's when I got into emulation. I modded the xbox to play classic games and that's when I found lots of nostalgia games that just didn't hold up.
Just about any Atari game, with the exception of Combat and Bomberman are no longer fun to play.
Most RPG's that were turn based are unplayable to me since they seem so slow. I played Ultima back on an Apple. I tried to go back and beat that game. I loaded up an apple emulator and .... zzzzz. I couldn't hang. I settled for watching a playthrough on Youtube, lol. Lots of the RPG's I played on Sega - I couldn't replay - they were just too slow. Everything on NES and SNES had no replay except FF3, I could replay that.
Galaga is my all time favorite game. I have a dedicated cabinet and I buy it for every mobile device/platform but I never sit down to play a game any more. With the games having no cost, I'm not motivated to play unless I'm on track to beat my all time score. Die on the first level? Shutdown and play a different game.
Ghost and Goblins is a great game but because it's so unforgiving, it's frustrating as hell. I only play this if I'm in too good of a mood and need to drop a few pegs.
Conversely, some arcade games I've been able to go back and beat. Rush'n Attack (Green Beret) is still loads of fun, Willow is a hidden gem, Zookeeper, Mr. Do, Robotron and Defender still get a good amount of play out of me.
Recently, I just modded a Wii and have been playing some of the console games I missed. I skipped that whole generation of consoles. I just finished the first Mario Galaxy and it was a blast. Going to check out the Metroid, Resident Evil series, and several other games before returning to Mario Galaxy 2.