Slimebeast on 30 May 2009
The developers of Prototype released Hulk already in 2005 (sandbox city game & super powers):
http://www.gametrailers.com/video/cyclone-hulk-ultimate/7141?type=flv
That's the main inspiration for Infamous.
But Crackdown was publicly announced at E3 2005. And a lot of detailed gameplay of Crackdown was shown in 2006.
Crackdown was released in Feb 2007.
Then Infamous gets publicly revelead at E3 in June 2007 with just a short teaser trailer.
So Infamous was probably inspired by Crackdown as well.
