Weird, I thought Gen V was pretty well-regarded? There was a lot of them, but Palpitoad and Throh and Sawk are some of my favorite Pokemon of all time now.
Anyway, I pretty much like every Gen (Gen IV, looking back, is probably my least favorite...and not because of the Evos, I like most of them, the other Pokemon are kind of boring outside Scorupi, Kricketot, Carnivine, Spiritomb, Snover, Hippopotas, Croagunk, Turtwig, and Gible), with Gen III being my favorite, and so far I feel these ones are pretty good, not too complex, but there's some quirky designs which I like such as Honedge, Helioptile, Skrelp, Spritzee, Flabebe and Honedge. I hope we get some humanoid ones, those are my favorite.
The only ones I don't care for much is Vivillion (Gen V had awesome bug Pokemon, shame to get such a plain Bug/Flying) and Fennekin, while Chespin and Froakie are neck-to-neck and I'm still deciding who to get. Oh, and Sylveon, but I never cared for Eevee evolutions, but I actually like all the other Fairy-types.