godaddy was the cheapest for me and right now they are doing $8.99 specials
But I actually use it for a shop, not just a central hub. With godaddy you have a lot of other options than just buying the domain. They will also host your site, etc, or you can always direct traffic to the domain name from another host, like Big Cartel, which is where I am.
ETA: in response to those who don't like godaddy because they "sell you other things", I told godaddy in their initial check up call to me that I bought the domain name and am hosting with Big Cartel and that's all I needed to domain for. They don't ever bother me. You can always opt out of communication too, by the way. That's a personal choice.