Which is most preferable Domain Extension ?

I think .com or .in is best and preferable domain extension.

It depends upon which region you are going to target your site.

It depends on your purpose. Domain extensions like .com and .info are the most popular. You can also try .org if it is for an organization, .edu if it is for education, and .gov if it is for goverment.

I agree with ghazia it depends which country you are targeting. I would use spammy domain names such as .biz or .info

hi,
I think .com domain is very popular. compare to other TLD, if you target any specfic targeted region go for CCTLD, which is more helpful. If your site is about some important information then go for .info domain name. It all depends upon your site.

It is depending on your site, if your site contents any education information then you can choose your domain extension .edu. If you have any organizations then use .org extension.
But generally people prefer .com extension first because if you have .com extension site then you can add any type of information in your site, which is more helpful. Top level domain is an ideal to choose as you can target different country which is not possible with country specific domain.

.edu is very good and effective domain.

.gov and .net is the best

Com is the best but you can use co.countryname and .org is the best