I don't have any really good robots, but I'm working on a couple of ideas that I think could turn out nicely if I tweak them enough... If any of my bots start doing decently, I'll post them.
I've made a nice class, /AGravEngine, which encapsulates the AntiGravityMovement algorithm. It's quite customizable, and includes support for things like custom power drops (i.e. Force = Pt_Strength / Dist^(Dropoff-exponent)), with seperate exponents for points and walls, a custom wall force, and custom point classes to allow things like variable strenth/position points. I also have the /AGravEngineGL subclass, with identical functionality, but which draws points to the screen with RobocodeGLV014.