Could you please elaborate which TLD you want to register? ENOM has released may new TLDs to choose and start a website and it is also helpful to earn ranking for your niche on search engines.
Ok, I can not tell you which is the best, and you can not believe in very cheap one. But I usually use from GoDaddy and Namecheap both Domain and Hosting.
Godaddy is good domain hosting website but it charges are very high. Big rock , namecheap, hostgator, and dreamhost are also best website hosting sites.