Bulbasaur is cute, Ivysaur is nicel, Venusaur is just lazy.
I mean, all gen 1 starters were nice improvements from one another.
Cute happy fire lizard, pissed off fire lizard, badass fire lizard-dragon.
Cute happy turtle, pissed off turtle, badass turtle-cannon.
Cute happy seed dinosaur, pissed off blossom dinosaur, and... Fatass flower toad-dinosaur thing.
Mega Venusaur is even lazier.
Also, Treecko is cool, Grovyle is cooler, Sceptile is horrible. Although Mega Sceptile does fix it.
I could go on and on, there are a lot of Pokémons that I loved when were first announced or I just found out about, but was entirely let down after discovering the evolution. That's why I simply can't play a Pokémon (or even Fakemon) game without knowing the full Pokédex before.
I agree with most that has been said, but I think Weavile is as cool as Sneasel, and Dusknoir ir immensely better than Dusclops.