What is the cheapest domain name register?

For registering new domains there are many websites like goDaddy, Namecheap etc. But do you know any website which give its domain registration services in really cheap price (I am only talking about usual domain TLDs)

I registered a .com domain at name.com at $9.8/2yr,that is $4.9/yr.I think that's cheap enough,plus you can get free whois privacy with a secret coupon code,just search it in Google.Whois privacy is expensive at godaddy

That is very cheap for a .com domain.