Domain name question

I currently own two domains for the same site.

blackburn247.com and blackburn.gb.com

My question is, which is the best domain name for search engine rankings? (in the long run)

Any feedback much appreciated

I guess everyone is confused by what I'm asking...

What I'm trying to say is, is blackburn.gb.com a better domain name because it has the isolated word 'blackburn' in the title, or does it not matter.

I want to get high up the rankings when people search for Blackburn.