KANTO
-Diglett + Dugtrio (what?)
They're based on whack-a-mole arcade machines. Dugtrio is three Diglett because more moles pop up the more you progress.
-Seel + Dewgong (it's a seal)
I like Seel. I think its dopey face and upside down pose give it character. Dewgong is admittedly very boring.
-Voltorb + Electrode (it's a ball with a face on it)
They're mimics! I love mimics in video games, and making the mimics lightning-fast creatures that only attack in self-defense is something new.
-Goldeen + Seeking (it's a fish)
...Yeah. Koi are pretty cool-looking, though.
HOENN
-Beatifly (Butterfree rip-off)
Yeah. Admittedly kinda pretty.
-Gulpin + Swalot (Grimer and Muk rip-offs, but looking 10x worse)
What, no, Gulpin and Swalot are great. Have you seen their mouths open? Looks ridiculous.
-Wailord (it's a whale)
It's a blimp whale. Wailmer is a balloon, Wailord is a blimp. Logical progression.
-Numel (what?)
It's a volcano camel with a hilariously dopey expression.
-Luvdisc (it's a heart-shaped... thingy...)
Discus fish. They actually are shaped like hearts.
SINNOH
-Finneon + Lumineon (it's a fish)
Yeah. I do like the butterfly motif.
-Rotom forms (...)
How is Rotom uncreative? It's a fantastic idea. You have a poltergeist Pokemon that possessed a TV, so its alternate forms are it possessing other machines with typings that suit what those devices do.
UNOVA
-Pidove (it's a pigeon)
Isn't that just Pidgey? All these birds look the same.
-Ducklett + Swanna (it's a duck and swan)
They're fairly elaborate designs, especially Swanna's ballgown-style wings.
-Alomomola (it's a Luvdic with fins. Congrats?)
Ever heard of the molamola fish? Admittedly, Alomomola really should have been the size of Snorlax. Also would have been a better Luvdisc evolution.
-Tynamo (it's a fish... thing)
It's a lamprey. A floating, weak, adorable lamprey.
-Beartic (it's a bear)
It's a polar bear. An ice polar bear. Admittedly, that's a bit obvious.
-Stunfisk (WTF is this?)
A cross between a stargazer and a flat fish. Might also have elements of the torpedo ray.
To clarify a little on my list: bad or ugly Pokémon design do not necessarily mean uninspired, else there would have been a Johto section and plenty more on the other region sections as well (with Bidoof and Patrat as the main entries on that list). Uninspired to me were mostly Pokémon designed too closely to real life animals and without enough cartoon to them to make them a little more unique, or Pokémon whose designs are too close to designs from previous generations.