I thought about putting down smooth tile on top of what's there, but I think it would get pretty expensive to get tile thick enough to handle all the cars and tools.
I'm starting to lean towards the rubberized floor panels if I can find smooth ones. That way I can do it a few rows at a time and I can always pull them apart if I ever decide to do a major garage cleaning again.
The ideal thing would be thick epoxy that could withstand tools and engine hoists but still have the tile look to it. The problem with that is that if it's too thin it can chip or peel.
I could always just put soft rubber tires on my tool boxes, creeper, picker and engine stands to smooth out the ride.