I'd only played the first game and for a short while at that, so my opinions won't nearly be as constructive nor reliable as those who have played it fully. I just didn't think it was very good; to say it was a watered down version of Prototype is an understatement. If it were any more watered down, it'd be drowning. The combat was poor, the story didn't stick, the characters were obnoxious and everything felt so unreal.... and not in the fun way. It was only a few months ago and the only thing I remember was the rooftop of the apartment where the two main characters spend most of their time.
I'd like to give other games of the series a try, and perhaps I'll give inFAMOUS another chance. Not now, but maybe next year or in the next lifetime.