In every single one of my games so far, Platinum and Soul Silver excluded, the protagonist was always named Hayden, my name, and the rival was always named Steven, after my best friend who introduced me to the games.
In Platinum, I decided to take an unique approach and name myself Osama and my rival Bush. I believe that although offensive, but I'm one of those people that likes to play Pokemon like it's real life... I give personalities to my Pokemon, I pretend that all battles are serious, etc. By naming them these names, I was able to take the game a little bit more seriously, and it made me rethink the whole Pokemon world, and how dangerous it would be.
In Soul Silver, I was Ethan and Silver was Silver. It was too mainstream because I'm a hipster generic for me though. My second-run through, and all subsequent ones, used my actual name if I were a boy, or my girlfriend's if I were a girl.