Second generation easily. The 3rd and 4th gen are just dumb and the 1st had good designs, but the 2nd gen really improved things.

I made this because I found that other poll interesting, but it was obvious some people were choosing their favourite game whereas others were choosing which Pokemon were their favourites. The OP didn't make this clear. I want to separate the confusion as I thought my interpretation of the last thread was more interesting.
 
This asks what generation had your favourite Pokemon overall. The first generation is the first 151 Pokemon and so on. The generation names are from Bulbapedia.

first gen. no doubt.

This is tough. the first and second were very consistant with great designs, but the third and fourth both have designs that I really like (along side a lot of crap). I'll go with the second, because it has the Cyndaquil/Larvitar family.

I'd pick First Generation.
 
Only for the simple fact that it was the generation that i got so used to, and truly loved. 
 
Sure you got your Togepi's and whatnot, but it'll never be as cool as Dugtrio.

" This recent thread already exists. "

Always first. 

That's a really tough question.

" @MysteriousBob: Was that edit there before I posted?  If so, I apologize.  Rectified it in my last post.  Edit: Or actually, I think it's because i posted it at the same time, before my edit... "

I'd say second.

I definitely vote on the first generation, the art was much more traditional, minimalistic, and, well, it was rougher. The Pokémon looked like fabled Japanese monsters, not like something that'd been pooped out of Photoshop using a formula to make the cutest possible creature.  

First. The later generation pokemon look either goofy or overly cute.

Second generations as well. They were still making them look like they could pick a fight and introducing new evolutions that didn't feel completely contrived (like whatever that new Magmar evolution is). Third generation has some winners, like Flygon, while 4th doesn't really have any that I care about...although Torterra and Lucario are really great. Second generation still has a good mix of 'useful' as well as 'well designed'. And no Bidoof.
But one thing stands true- you can't fucking beat this shit
 

" @MysteriousBob: Well, art techniques are a large factor as to what makes art design so interesting. We're talking more about the art design than the gameplay functions, aren't we? "

There isn't even a debate here, its the first generation in every way.

" I'd pick First Generation.  Only for the simple fact that it was the generation that i got so used to, and truly loved.   Sure you got your Togepi's and whatnot, but it'll never be as cool as Dugtrio. "

Pokemon sucks in general...never really got into the game myself.  I mean if someone walks up to me and says "Lets battle" and then throws some red and white ball on the ground and some weird creature comes out of it.  And then he says "Overly cute creature, that is small enough to fit into my anus, ATTACK".......I would probably pull out glock and shoot it in the head, and then I would say "I WIN"
 
   Yea I never really liked Pokemon or Digimon or any other of the "mons" of the time.  There is just something creepy about kids who walk around with creatures they can pull outta there ass at any moment.  I mean they could easily over throw a small country.

1st. It was a simpler time, it was an awesome time.

1st gen.

Give me Blastoise any day.

I'm attached to the Gen 1 pokemon, cause I grew up with them. It's hard to consider any of the other generations designs "better".