I've been playing games since pong, atari, intellivision, and commodore 64. So many games, and kinds of games that I can't possible list them all here. Not sure about it increasing memory or not. I definitely do believe that it makes you smarter in some sort of way, but not sure in what way(s) exactly. One thing I do know is it increases your reflexes sooo much. I seriously have lightning-fast reflexes - if something (say a glass) falls off of a counter (or anything of that sort) I have literally seen things fall in slow motion before and snatch them out of the air before they hardly even started falling. Amazing and weird but definitely a fact. Of course most people don't waste as much time playing video games as myself.
some of my favorite recent games,
The Saga of Ryzom
EVE Online
Battlefield 1942 (w/ Desert Combat mod)
Ground Control 2
Warhammer 40k: Dawn of War
Immortal Cities: Children of the Nile
Railroad Tycoon 3
Grand Theft Auto: San Andreas