Hm, tough. I personally like Pokemon more than Digimon, but if I were a Digimon I could talk and be Renamon with her awesomeness.
I'd still have a tough time deciding, Pokemon or Digimon, because I know all the Pokemon but not so many Digis... after all, phsycic powers like Gardevoir(woo!), flying like most phsycic types and flying types, breathing underwater and land like Mudkip(awwz ^^)
...Um, since I'm more experienced with and know more about Pokemon and all of the different ones, I'll go with that. Gardevoir has flying and phsycic powers, so I could just create a phsycic air bubble to breathe underwater!