If you are asking about which pools are more profitable, I took some time today to answer this here:

http://bitcoin.stackexchange.com/questions/36725/btc-hashes-second-rates-for-various-pools/36747#36747

You will want to consider other things like is the pool reputable? If they ever reached a too-high concentration of hashpower, how did they handle it? Have they been involved in scams? Have they confiscated miner funds for dubious reasons? And which is your personal favorite? You may want to try a couple pools and see how you like them.

All of the above may be more important than a small difference in mining income.