SparkPool.com is a Global Ethereum mining pool that was initially called Ethfans. Currently, using a PPLNS system and has a minimum payout of 0.05 ETH with a 1% fee. (Difficulty set to 4 billion)
The Onion Pool is an Ether mining pool that currently charges no fee. It runs on a prop payment system and rewards miners with the block tx. fees as well. The minimum payout is 0.01 ETH.