I love all the generations, gen. 3 especially.
I - RB were the first, so instant classics. And, back then, pokemon was seriouslly Bad*ss, it seems like Tajiri almost didn't care about contraversy. Pokemon dieing, Jynx, all these things make them seem a little more towards older audiences
II - The low levels were most likley because of the spread between 2 regions, and Kanto being a nuclear wasteland couldn't be helped, the game's memory were packed full, not leaving much room, yet people always complain about which makes no sense! But on the giood side, it introduced awesome Pokemon, new mechanics that would shape the future of Pokemon, with the mix of new age tech and old style surroundings, they were great games.
III (RSE) - This one recieves a lot of critisizem, even though it was a HUGE step up in terms of graphics and even mechanics. Even though the water routes were a tad annoying, it doesn't hinder team building, it is a change from walking around everywhere. The Pokemon also don't get a lot of respect, but why? They are AMAZING, and it's good that they're getting more and more creative, so it's not just bland lookin'.
III (FRLG) - A big step up from RBY, with more detail, aesthetic changes, the Sevii Islands, which were planned to be put in RB but didn't make it, these were a bit of just a rewash, really, but it also let people (like me) get to travel through Kanto for the first time even though the originals are out of our age. Great games, but a little could've been changed.
IV (DPPt) - Also a big basher's target, these games were almost as big of a step up from Gen. 3 as RS was to GSC. To me, it has a fresh feel, although they didn't throw in a remake between DP and Pt, like with RS and E, so Sinnoh did get a little boring, but the Sinnoh region introduced some fairly cool looking Pokes. Although the evil team was stupid, and they went overboard on the number and abilities of legendaries, the region still has a kind of, new feel. And it does start to gear more towards competitive battling, but all in all, the graphics are nice and the region is fun to explore with all of its different terrains.
IV (HGSS) - Despite being a remake, the Johto gyms still SUCK in terms of levels and Pokemon, but again with the 2 region spread. The updated graphics are nice and there are plenty of things that make you go, "Nice touch!". Pokemon following you, it would've nice if they would've added an option of not having them follow you, but ya know. The awesome graphics and new features, these seem to be great games (although I've not played them yet...).
All in all, people must be really bored or just in a bad mood to bash the different generations. They are all great in my mind and people need to stop bashing just because there's a few bad things. It's annoying.