Well, for starters, I'd like to point out that the show is intended for ….CHILDREN! Most of the reason they don't change things like the main character is because the fans will complain (the kids) and it is just as easy to keep them and recycle the things they do.
Having said that, the "rival" character in D&P is awesome (Shinji). He sota has a Sasuke-type personality, but other than that, he has to be the best battler on the show. He schooled Satoshi in their 2 fights and refuses to fight him again. He also beat the Kurogane City gym leader without cheating (Satoshi cheats like always...). Like the games, he releases pokemon that do not have the moves he desires. For some reason, the other characters think he is cruel for releasing them (zOMFG you have to be friends with all of your Pokemon!).
Satoshi sucks. He doesn't know how to battle (He ALWAYS throws out the pokemon who is weakest to the one he is battling) and refuses to evolve any pokemon. Pikachu should be the strongest on the show but he becomes weaker each episode. The reason he has an Eipom is because it has a new evolution in D&P.
Oh yeah, Hikari blows too. She loses her first contest (to her yuriesque rival) and only catches the "cute, contest pokemon" (pocchama the penguin, mimiroll the bunny, and pachirisu the squirrel...). She whines about losing her contest despite the fact that she never even trained Mimiroll at all (the reason she lost; it lost a "contest battle").
As for Movie 9, it is the best movie without a doubt. I do not watch pokemon in english (I have seen the first series in english), but the movie is very good for being a pokemon movie (If you have played at least half of Zelda: TP then it will seem even better because the Sea Temple looks alot like the underwater temple in that game).
D/P is a very fun game. All of the gyms have something special about them (Elevators, traps, switches, etc.) and the pseudo-3d aspect of the game make it look nice (It has a bad framerate though). I'd recommend the game to anyone who like pokemon originally and has a DS.