corrosivefrost
Member
It's been reviewed 255 times and the current standing is "Very Positive". I'm sure there are at least a few that go into some depth if you need more convincing.
I'm sure you meant this to be solely informative, but I can't help but detect a bit of the irritation I normally feel when reading questions like this underneath it.
NeoGafs sale thread. If that is down, you can always use SteamDB.
Isthereanydeal
Neogaf Sales thread
CheapAssGamer is also pretty useful
The NeoGAF sales thread is normally a cesspool of randoms asking if a particular game is "worth" a certain sale price, if games on sale are expected to go lower later in the sale, or discussing the meta-game of the moment. Sorting through all that to find the sales data is more work than it's worth.
Occasionally Toma puts together this "indie games/overlooked deals" thread that you can use to find some really cool things you may have overlooked. But other than that, your best bet is to check Steam itself, check your wishlist, or go through isthereanydeal if you have a specific game in mind.