some are great deals and others aren't
Check out this link for help on that
www.cheapshark.com/browse?storeID=7
mouse over the game and click the I button that pops up. This will show you if it is the cheapest price right now and if it is the cheapest price ever.
Also for steam fans, here are the four games on sale that will activate on steam
Tomb Raider
Hitman Absolution
Plants vs. Zombies
Sleeping Dogs Digital Edition