btcguild is best
btcmine is second
deepbit is the worst
slush is the best of all the paid pools.
Is this based on anything other than what you use?
I have used most of the pools at least once. deepbit has such a high fee and it doesnt provide as many stats as other pools do. i prefer slush i like the way the site is laid out more and the fee is 1btc off the top of 50btc from the block.
now a days i dont see much of a point of being in a pool with a fee with all the free pool options around. if you want to mine in a pool and pay for it just donate to a free pool and get the minimal extra benefits. On btcguild for 2.5% donations you can cash out whenever you want and you get paid for invalid blocks.