Best OCing CPU

Ok guys I have two questions. The first one being..... What is the best Overclockable CPU. Now I don't mean Ratio wise. I mean actual clock speed. Which AMD will give me the absolute highest frequency? I'm running dual athlong XP 2000 Oced to 2200. I'm wanting to make a really good gaming system. That's all it would be used for. Just gaming. Nothing else. I want to know what would be the best Procecssor to Put under the hood and the best motherboard to put her on. I'm watercooling so I'm going for highest clock. So lets hear it!