"best" is subjective.

If you would like to be paid in BTC, NiceHash is by far the best place to rent your hash.  Check their stats.  They regularly state the payments that go to sellers of hashrate exceed what you'd get by mining with 100% luck, and in many cases by quite a bit.  Just use their internal wallet to keep the fees at 2%.  (My sig has a referral for them.)  At the moment I have no reason to believe they are fudging their stats.

If you want to play with other coins, Prohashing can pay in you in many different coins.  However it's a 5% fee.  If you think you can compensate for that fee by playing a coin, that may be best.

I think there are a few straight Dash pools as well.  However I don't know what they are.  Read back through the last few pages of posts to see.

Lastly, keep your electricity costs in mind, unless you are doing this for fun.  Otherwise it may get a bit stressful.

M