NO!
Not only are there immediate genetic risks, which very depending on your and your "spouses" genes, but think of the long term damage to the overall gene pool. I dont want everywhere to look like Tennesse! :p Sorry, my wierd sense of humor again! (no offense everyone from there!)
Anyways, also, many scientists that are studying Egypt believe that continues incest relations is a big part of why that nation eventually faded to extinction.
PLUS, YUCK! Do you really want to marry your Uncle or 1st cousin? I dont know about you, but "keeping it all in the family" is a bad idea!