Like a few others, I wasn't a big fan of GTAIV. It felt like a step backwards to me. I can live without the customisation of CJ in San Andreas but fewer weapons and no planes feels a bit odd. I enjoyed the mini-games and being able to watch television (as long it wasn't Ricky Gervais) but they were more like nice little touches rather than anything I'd buy the game for. I found the cover system particularly bad.
I'm looking forward to the GTAV trailer though and, if it's a current-gen Vice City, I'll be very excited.