I've used a number of different registrars, and the one I keep coming back to again and again is DreamHost. I don't know whether you need to host with them to use them to register domains, but ... here's what I love about them: DreamHost makes it really really easy to move your domains away from DreamHost. That sounds counter-intuitive (if they're so good, why would I want to move them away?), but it isn't. When you set up an account with GoDaddy (or other registration services), if you later decide that you want to change your registrar, they have a CRAZY process that you have to go through where you have to get an e-mailed code, that you then have to enter back into a random form at GoDaddy's site, and then you have to do something else, and only THEN do you get the authorization codes to actually move your registration. At DreamHost, those auth codes are one click away. And that's the kind of thing they do: They make it easy to work with them. And if you ever decide you need to move on, they make it easy to stop working with them.

So, yeah. I don't get any kickback or referral for referencing them. But you should absolutely check out http://dreamhost.com.