After seeing trailer #4 I bought a 360, and pre-ordered GTA4. Does that answer your question? ;)
PS: Before that, I was waiting for reviews and people's opinions to make a decision, after seeing the trailer I just decided to get it (although the good 360+GTA4 promotion I found also helped; the 360 is really cheap now in Europe).
My Mario Kart Wii friend code: 2707-1866-0957