SR 2 has a better story, more missions, the enemygangs are better, better writing, better side missions (they left good ones like Hot Fuzz, Septic avenger and others out), the character customization in SR2 is better(example: the gender slider is changed, you can`t create a really thin looking guy in the third. They keep their wide shoulders), three fighting styles, stilwater (more varied locations with more varied people - go hunt fratguys or emos in the university district or scare the yuppies downtown), a cutscene viewer, mission replay, a real mean main character.
SR 3 has better graphics, better gameplay, the action button, animated hair(looks like plastic), a few awesome storymissions, online character sharing, bulletholes.
I was a big SR fan and i love the second. The third is great for freeroam but there is to much i dislike and miss. They changed the tone and direction and now there`s sci- fi stuff and a wierd story. It`s overall less detailed and thoughtout (activities as storymissions just for the stretch, steelport looks good at first but then it`s just boring, the only switch is between industrial and skyscrapers).
It`s all a bit to silly/over the top now for my taste and i hated the changed characters and the overall writing.
This all sounds pretty downing for SR3 but you will have fun with it (freeroam+action button=win). From the tech side this game owns SR2.
@Jynthor
I should have watched that review before posting. It owns my post. Best detailed review of the third i´ve ever seen. Angry Joe has the same fear about SR4 and after the sucess of the third i doubt they will change the direction again.