Starcraft and Expansion.
Crusader: No Remorse
Outpost 2 (By the way, this is a really fun game.)
System Shock 2
I've bought Neverwinter Nights 4 times. (Original, Gold, Diamond, Diamond again because my father in law fell in love with it and I didn't have the heart to ask for it back.)
I can't find the CDkey for Company of Heroes, something I bought last year.
EDIT!: StarFlight for the Sega Genesis. With the wonderful manual (100+ pages, including in universe fiction). I'd pay good money to have this again.
Post edited October 27, 2008 by Joush