Yeah, I agree with you about the designs. I don't think the designs after 2 and 3 are bad, but I don't think they're as good after that.
I think the reason I like Johto and the gen 2 games is the music and the Pokemon designs, I love the post-game in Kanto as well. I actually started playing the games in 2004-ish (mostly because I could read at that point and time) and my parents were super cheap and wouldn't buy me a Gameboy Advance so I got a hand-me-down GBA with Pokemon Crystal. I never actually played B2/W2 just because I had enough of Unova in the first games.