God of war is the best in the genre, it is what all other action platformers are compared against. The first two god of war games are brilliant HD ports of the original PS2 games and still very fun to play, the two PSP ports definitely have weaker graphics and the controls are slightly off (PSP doesn't have the same triggers so your actions are slightly different), but still very fun and worth playing. God of War 3 is beautiful, engaging, amazing. Easily one of the best PS3 titles.
So basically, buy this, they're great games, you won't be disappointed!