lol yah i know most of you won't believe but i have a low specs pc too.(almost the same as you)
i have intel core i3 2.1 ghz,2GB Ram,Intel hd graphics
and i can run call of duty modern warfare 1 with perfect fps on low,medium options (it is playable on high settings but i keep it between low and medium to get high fps in the game)
anyways also you can also run sims 3,ballance(trust me this is a very great game to play while bored XD,delta force series,need for speed underground 1+2+most wanted,halo 1+combat evolved(lol they are the same game i didn't find any differense between these 2 games when i played them not even the menu screen or levels xD),serious sam the 1st+2nd encounter and serious sam 1(i don't know about 2 never played it before),prince of persia : TSOT+WW,all sonic pc games but not generations,portal (the first one not portal 2),Transformers (the first game only)all TMNT Games,counter strike from 1.1 to 1.9 and condition zero,Rayman 1,2,3,Crash bandicoot series(u may not believe but i really played them on my pc before)
well i think that's enought.
u can always play the old gaming consoles(GBA,Nes,SNES,PS1,Sega geneses,etc)using emulators