off the top of my head:

Bioshock II & III (I wasn't in love with the first Bioshock and I mostly just want to play III, but I will kick myself for not playing two because OCD)
Dark Souls
DragonAge
Fable I & II
Ico
Mass Effect I-III
Myst (I have always always always wanted to play this smurfing game goddamnit)
Persona
Portal I & II
Red Dead Redemption
Skyrim
The Last of Us
Vagrant Story

and a lot of others Pretty much any game of note that I've been missing out on for the past fifteen years. I have a huge list I need to get through someday