Good question Alex!
The only other concept I've heard about other than the rubber sheet analogy is the graviton particle theory. In practice they are probably the same... at least until experiment can distinguish one from the other, and see which one is closer to reality.
I'm not sure that I'm particularly up to date on gravitational theory or particle physics, but I believe the graviton is predicted by one or more theories but hasn't been detected
. Is that right?
...of course there's always the old faithful "Gravity sucks" theory!
Al.