I mined at btcguild, triplemining and st Eligius pools, they are stable and reliable pools. But then I read on bitcointalk about a new pool: CKPOOL made by: ckpool code by ckolivas and ckdb code by kano.
You can mine at http://www.kano.is with PPLNS reward with (only) 0.9% fee. It has a great performance. I mine at this pool for some days now and I see it has better performance than other pools I used before.
If you are a real dare-devil: mine SOLO at http://solo.ckpool.org. This pool is awesome, you mine together with other miners to find a block but if you are the one that finds the block you will get the whole reward of 25 BTC!! (minus a small fee of 0.5%). It is anonymous, just mine just with your walletaddress as worker, no registration required. I know the change you will find a block is very smal, it’s like a gamble but it is fun and exciting.
So come on fellow miners , join us at http://www.kano.is and http://solo.ckpool.org
Here is a quote from Ckolivas about CKPOOL:
Ckpool is a project by the cgminer development team designed to complete the circle between miners and pools from cgminer to ckpool. The bulk of the code work for this was commissioned and paid for, however I provided an incentive to the group commissioning the code to open the software up to all by charging less for free software than for closed code. Ultimately this should benefit bitcoin far more than me simply working on code for another pool. I intentionally chose to write most of the code from the ground up and not use external libraries to have complete control over all the code given past experiences of difficulty to debug failures in library code that was outside our domain with cgminer. The separation of the pool code from the database code allows the pool code to be ultra-scalable and extremely low overhead by dissociating any concept of share counts, user accounts, authentication, front ends, payschemes etc. etc. These can be as vastly different from the envisioned ckdb+postgresql+php interface as the administrator desires without any change to the core pool functionality.
UPDATE [NOVEMBER 1 – 2014]
The CKPool www.kano.is is doing great ! More miners joined and total hashpower had grown to 600+ THs and the pool has found 4 Blocks already in just 1 month ! So join us fellow miners !