Usually people go to Illustrator because it's easier in terms of workflow (reuse elements, manipulation and such), but all pixel artists are most likely to use Photoshop instead.
If you mean style, you may check on Braid, a platformer with a nice paint-ish feel and interesting time mechanics.
<img src="http://images2.wikia.nocookie.net/__cb20100507135312/tig/images/5/52/Braid-screen01.jpg" border="0" />