Well everyone's entitled to their opinions. I personally thought Gen V had some pretty solid designs. At first I didn't like alot of them , but now after playing the games, they've grown on me. Now I have alot of favorites such as Braviary, Scrafty, Krookodile, Carracosta, Joltik, Litwick, Whimsicott, Volcarona, Bisharp, Hydreigon, Sawsbuck, Lilligant, Joltik and there's probably more. They felt different to em at first , but new Pokemon always seem to do. Though I think every gen has some bad and odd designs in it.
Now for Gen VI, looking at the starters and new legendaries, I think so far there's some pretty well designed Pokemon. I personally think Xerneas and Yveltal are the best designed box legendaries since Gen II and the starters are better looking than gen IV and V's starters. Though that's all just personal opinion.