I like to hold on to my games, partially because I'm a casual collector, partially because I figure someone will want to play them later, and partially because I inherited some of the gene my grandparents have wherein it's nearly impossible to get rid of anything. The only games that were bought, played, and sold/exchanged for store credit in this house were, in no major order:
-Game and Watch Gallery 4
-Spyro: Enter the Dragon
-Rayman: Hoodlum Havoc
-Billy Hatcher and the Giant Egg
-Amazing Island
The latter four were games given to us or bought mainly by my brother, though.