I admit, I got pretty sick of Pokemon after a while. My first game was Emerald though, so the R/S designs really didn't bother me. When Diamond/Pearl came out however, I just wasn't feeling it. I didn't like the designs as much, but my problem was that it was the same exact game over and over again. For some reason they got away with that for the G/S DS remakes. I absolutely love playing those. Black/White will be interesting though. I was ready to call HeartGold the last Pokemon I would play all the way through, but the new additions make it look like a worthwhile experience. It's also kind of awesome that none of the old Pokemon will turn up until after you finish the game, because seeing the same Pokemon mixed with the same gameplay was really annoying, especially in such a grind-y game.
I look past the designs of the Pokemon though. I find first and second gen are still my favorites, but it doesn't mean I'll refuse to skip out on some goofy ass designs when the gameplay is good. I do hate when I have to pay full price for a game that is no different than the last one, and I hated having to buy multiple versions of the game to "catch em all" (They remedied that with HG/SS to an extent though).