Zombie Genocider: Defeat at least 53,594 zombies
Is it one of the most annoying achievements ever? Yes.
Is it worth it? Yes.
Anyone who has this achievement will likely be considered a whore, a real juicy, nasty whore. I recently went through the agony of running over zombies over and over and over. I hated it, but it was all worth it to me. The reason behind this is because you actually get something in-game for doing this. Have you ever wanted to beat down some zombies as Mega Man!? Well you can't do it in this game, but you can blow some heads off! Is that good enough for you? No...then you can go eat a sausage!
I just want to tell anyone who attempts this amazingly horrible feat that you will hate this game immediately after it's done. You will want to take the game and set it on fire!.... Right after that you will want to take a massive corn-filled dump all over it...and then once all that has had time to settle in; you will finally be able to clean it up and start playing once again, but now you will have the aid of the real Mega Buster. Now take that weapons of mass destruction and bust some zombie sausage!
*EDIT*
I HATE YOU Dead Rising! Why did you freeze on me during Infinity mode? huh...you are a dirty bastard and I truly hate you. You do know I can't save in this mode and thus would have to start from the beginning if I want to make a second attempt. What's that...you think it's funny...STOP LAUGHING! I hate you Dead Rising and I hope you burn in hell!!!