.co is a favorite among non-VeriSign domains.

Registrars have many options when it comes to which top level domains to promote to customers. Sometimes this is based purely on demand calculations. In other instances domain registries strike deals with domain registrars to give them premium shelf space or promotion on their home pages.

I just checked the top 10 domain registrars. These results are for either the drop down box in their domain search function or the results page when you search. Excluded are reseller-only registrars that don’t have a consumer facing site. I’ve also excluded MelbourneIT because they seem to be having web site problems right now.

GoDaddy

.com
.co
.info
.net
.org

(notably, .me, which is backed by GoDaddy is #6)

eNom

.co
.com
.net
.org
.info

Tucows (Hover)

.com
.net
.info
.co
Then usually shows another variant of .com

Network Solutions

.com
.net
.co
.org
.biz

1 and 1

.com
.co
.net
.org
.us (I suspect this varies depending on your location)

Register.com

.com
.co
.net
.org
.xxx

Moniker

.co
.com
.org
.net
.asia

Source from http://domainnamewire.com/

Now the .asia domain only cost 6.9 USD for the first year
other domain name you may need.
.com  only USD 9.77/year
.net   only USD 9.77/year
.hk    only USD 22.63/year

To register your own domain name, check out :
http://www.eranet.com
http://partner.eranet.com