Well, there are a kazillion threads here discussing that question -- we have an entire forum devoted to that specific issue!
http://allnurses.com/forums/f283/
I'm moving your post to the Registered Nurses: Diploma, ADN or BSN? forum, since that's your topic, and encourage you to look over some of the threads that are already there -- lots of good info, discussion, and opinions.
Good luck with your search!