Gameloft, in particular, are having a $.99 sale on some of its most popular games: Hero Of Sparta, Brothers In Arms, Terminator Salvation, Blades Of Fury (my favorite), Shrek Kart (which I just bought), Real Tennis 2009 and Castle Of Magic.
I also bought iGOG: Massive Drums [iTunes link] which has amazing touch-sensitive touch pads that makes live drumming on the iPhone a real possibility. It also has a recording feature. iGOG is on sale for $2.99 down from $4.99.
AppShopper.com has a full list of all the apps that have price discounts.