Ummm....this is going to be hard. My knowledge of the WaterBeetle is limited, but here goes. The '98 model was equipped with laser-targeted turreted machine guns while the newer models have since changed to straight-out laser targeted lasers. One important change in the '99-'00 models is the addition of a rudder and wings, each able to "pop out" at 258 mph. The only problem with this, though, is no one has been able to achieve 258 mph. My favorite feature is the '02's ability to warp to other times and dimensions. I hear this is how the VW Beetle was started. One of the purple colored ones went back in time to run Hitler over...instead, it landed on a sheepherder in the German countryside, leading to rumors and visions of a new car that everyone could afford, even a sheepherder. :baaa:
So, with all these cool options to choose from, my pick has to be the '52. That was a choice, wasn't it?