If you're a fan of first-person shooters, you'll probably want to jump on this deal. MC3 has gotten quite a bit of praise. Just be warned that it does require 1.4 gigs of free space for the data install.
Of course, if you aren't a fan of FPS games, all the other Gameloft games are still on sale, and there are a number of good ones in that batch. If you want Modern Combat 3, just head over to the Android Market.