I used to play a variety of genres..

I love FPS like Serious Sam, Duke Nukem, Doom, Quake..
I love RTS like Starcraft, Warcraft, Dune, Age of Empires, Cossacks, Dungeon Keeper, also Majesty 1 & 2 who are great fun..
I love RPG's like Diablo, Baldur's Gate, Dungeon Siege and more.
but most of all I love to play strategy games like Myth/Myth 2, the Total War series which is my favorite of all times..
I also love space games like Wing Commander series and can't remember the rest lol..

there is one great game which is free and I played a lot on this laptop until I coudnt play anymore is PathofExile, lot of fun and its totally free to play..