People often complain about the designs of Pokémon: "This Pokémon sucks because it's just an inanimate object", "That Pokémon is lame because it's unoriginal", or whatever. But what, in your opinion, makes a Pokémon design good or bad? Is it the coloring, what it's based on, or something entirely different?
It should have an interesting look. It shouldn't look like a mashup of shapes or other Pokémon parts coming together.
A good colour scheme can win me over! I'm also a sucker for big eyes. But that said there's not any Pokémon I would personally class as badly designed. Just differently designed!
Like Aero said, I don't really think there are bad designs in Pokémon, but there are ugly designs, and cute designs, and beautiful design, designs that are just laughable, but all these are dependant on the taste of the "trainer". Not to mention that some Pokémon were specifically designed with the region in mind already, which makes them fall out of tone in the other regions.
I don't mind inanimate objects but sometimes they're just not... interesting or feel really, really lazy. Doesn't mean simple, just... lazy. Sometimes I'm called a genwunner for not liking most designs from gen 5, which is funny now because I really like most of gen 6 and 7, making me say "WHERE IS YOUR GOD NOW?" A fine point could be also made because we have those Pokémon that are tokens on every gen, like bird Pokémon, and... sometimes their design is good but they can feel like "ok, it is just another one of those..."