Sacrifice Rooms

Historically, Sacrifice Rooms have always been pretty darn useless in The Binding of Isaac, but lucky owners of the Afterbirth DLC will find they've had a huge revamp, significantly increasing the quality of rewards you can find.

The Sacrifice Room now has various different levels of rewards, depending on the amount of times used on the same floor. The below table details each level of payout and the reward for reaching each tier:

Number of Sacrifices	Possible Payouts
1st, 2nd	1 Coin (50% chance) - Cannot be Nickels or Dimes Nothing (50% chance)
3rd	Nothing (33% chance) 'You feel blessed!' buff (66% chance) - Increased chance to see an Angel Room in favour of a Devil Room on the current floor - This increased chance has a value of 15% * (Devil Room chance).
4th	1 Random Chest (50% chance) Nothing (50% chance)
5th	3 Coins (33% chance) - Cannot be Nickels or Dimes 'You feel blessed!' buff (66% chance) - Increased chance to see an Angel Room in favour of a Devil Room on the current floor. - This increased chance has a value of 50% * (Devil Room chance).
6th	Teleport to the Devil or Angel Room (33% chance) 1 Random Chest (66% chance)
7th	1 Random Angel Room Item (33% chance) 1 Soul Heart (66% chance)
8th	6 Troll Bombs (100% chance)
9th	Uriel Angel mini-boss spawns (100% chance)
10th	7 Soul hearts (50% chance) 30 Coins (50% chance) - Cannot be Nickels or Dimes
11th	Gabriel Angel mini-boss spawns (100% chance)
12th+	Teleport directly to the Dark Room floor (50% chance) Nothing (50% chance)

A big thank you to Zamie who did the research and added the above stats to the Sacrifice Room Wiki page.

Notes:

The 'You feel blessed!' buffs can even allow an Angel Room to spawn after taking a Devil Deal.
A payout is randomly chosen from each of the possible ones for that sacrifice.
The sacrifice room door stays open during the Angel fights, meaning they can be skipped to proceed to the next level of sacrificing without killing them.
The Dark Room teleport still happens on any floor even if you haven't unlocked it yet.
Dying in a sacrifice room while holding Missing Poster will unlock The Lost.
Invincibility and shields will not trigger a sacrifice (including Holy Mantle).