Pokemon Contests, but only if more intricacy were added. Never got into Contests really, but I'm pretty sure you couldn't pull off most of what was in the show.
Would also like to see more breed-only pokemon. Not babies or Phione, but a seperate evolutionary chain that can only be obtained by breeding 2 specific pokemon/types together. Some could be new pokemon, some alternative ways to obtain unobtainable pokemon, like breeding Squirtle with a grass type to get Turtwig.