Purugly is ugly...
But Gyarados is scary ugly.
Bibarel is the ugliest pokemon with that new mushroom pokemon (the evolved form, anyway) coming in a close second.
To me, Bibarel is one of the very cutest pokemon, which goes to show that it's all in the eye of the beholder. ;)
Propobass. It has a good origin and reasoning behind its appearance, but that doesn't prevent it from being horrendous.
Propobass, Gamageroge, and Maggyou are all unappealing to me.
Aside from Feebas, Magikarp and Basurao, I think that Hitmonlee, Mamanbou, the whole Kami trio (Tornelos especially), Sunkern, Purugly, Hypno, Baruchai/Barujiina, Morobareru and Crimgan are among the less appealing. The three last are also annoying, which makes them even uglier on my eyes.
Hippowdon, especially the male. Unappealing, revolting, and simply hideous.
Hippowdon looks cuter with his mouth shut.
Hippowdon is beautiful?! In a deadly sand-hippo way, y'know?
most gen V are ugly [especially the one who look like alien]
But for me the ugliest is Snubull ang Grandull
I don't like Daikenki....It goes from a extremely adorable otter, to a badass yet cute looking otter, to a ugly sea lion thing with a huge mustache. Thay is why I'll keep my starter in the Futachimaru stage.
Jynx... She = ug-ug... Oh and Magmar!
Wooper was pretty ugly back in the GSC era... I blame the sprite.
Smoochum and Magby... Just butt-ugly. Barfable.
And that's all I can think of... *shudders*