Here's a link to a nice archive of Crysis 1&2 concept work.

Enjoy!
http://www.incrysis.com/index.php?option=com_incgallery&task=viewcat&cat=artwork&p=0

This one is miscellaneous renders and such.
http://www.incrysis.com/index.php?option=com_incgallery&task=viewcat&cat=misc