I use Crucial Web Hosting. For $5/year it ain't bad at all. I tried Yahoo one time, but it was a pain to transfer because I couldn't find the EPP (or is it EOP) code anywhere. Besides, I use Crucial for hosting too so it's nice to have it all packaged ya know?
I will NOT use GoDaddy either, heard too many complaints about them and had trouble of my own. NameCheap.com isn't too bad either, but like I said, I prefer the hosting + domain package together, it's just easier for me to pay one company instead of two.
Cheapest? Not sure. I know you can find somethings for like $2-3 I'm sure, but there's got to be some kind of catch or something.
Anyways,
CrucialWebHost.com if anyone's interested, otherwise I recommend NameCheap.