Here's what I didn't like about the previous GTA's
1 & 2 top down perspective. random.
III -- poor graphics. It felt like it had a tacked on story. The central character has little to no personality.
VC -- Didn't play
SA -- didn't like the characters. Don't care enough about hip hop to play a long game with those types of characters.
IV -- realistic story, great graphics, strong central character I could identify with.