As per usual, there are daily deals, twice daily deals, and the Community Choice picks which seems to rotate every 24 hours.
For the next 48 hours (since the daily deals go for two days with a day of overlap between days), you can get the following items on sale:
Sniper Elite 3 - 50% off - $24.99 (USD)
Space Engineers - 50% off - $9.99
Eurotruck Simulator 2 - 85% off - $3.74
State of Decay - 75% off - $4.99
Total War Rome 2 Emperor Edition - 75% off - $14.98
Dark Souls 2 - 63% off - $14.79
Civilization Beyond Earth - 40% off - $29.99
Rocksmith 2014 Edition - 66% off - $20.39
Metal Gear Solid V: Ground Zeroes - 33% off - $13.39
Space Engineers - 50% off - $9.99
Eurotruck Simulator 2 - 85% off - $3.74
State of Decay - 75% off - $4.99
Total War Rome 2 Emperor Edition - 75% off - $14.98
Dark Souls 2 - 63% off - $14.79
Civilization Beyond Earth - 40% off - $29.99
Rocksmith 2014 Edition - 66% off - $20.39
Metal Gear Solid V: Ground Zeroes - 33% off - $13.39
The current as of this posting "flash" sales (the ones that change every 12 hours) are:
Hegemony Rome - 85% off - $4.49
SpeedRunners - 75% off - $2.49
Microsoft Flight Simulator X Steam Edition - 80% off - $4.99
Damned - 75% off - $4.99
Injustice Gods Among Us UE - 75% off - $4.99
Styx: Master of Shadows - 50% off - $14.99
SpeedRunners - 75% off - $2.49
Microsoft Flight Simulator X Steam Edition - 80% off - $4.99
Damned - 75% off - $4.99
Injustice Gods Among Us UE - 75% off - $4.99
Styx: Master of Shadows - 50% off - $14.99
You can vote on the Community Choice selection every day. You will get a special holiday card for doing so.
Side note: I only did a Google image search for "wallet burn" intending to get a picture of a wallet on fire no thanks to Zips' constant reminders of sales. But lo and behold, this shows up in the results proving the impact and destruction Steam has on the world economy as we all fall into a new global recession minus Valve.