I cannot believe that nobody has said Nidoqueen!!! :(
If at first you don't succeed, warp reality till it fits your demands ;)
claimed Ekans on 10/28/2012 and all has been well in the world ever since. :)
I'm likely to get hate from this, but either Skuntank or Crobat. I think Skuntank is a rather underrated Pokemon. I bought a used Diamond copy back in December to replace my copy which I lost and decided to catch some Pokemon on the current save before resetting. The last guy had a Skuntank and I decided to use it. It ended up being stronger than I expected. Sure not the best Poison type, but not the worse either.
Crobat, has a good design and pretty makes up for how bad Zubat is.
I don't use "uber" Pokemon, I don't calculate stat values, I don't use cheating devices, I don't breed my way to perfection, and I don't care about natures. I catch my Pokemon the way they are, and treat them like individuals instead of brainless drones. If you use this philosophy, copy & paste this into your signature
I have claimed the Spell Tag and Kasib Berry, along with Adaptability and Shadow Ball. I have also claimed Gastly.
If you think Nintendo need to sue PETA up the ass for making Pokemon Black and Blue, copy and paste this into your sig.
I realized that there are quite many of them even though I´ve never considered poison as my favourite type. (Maybe it´s because many grass types have poison as their secondary type).
So, considering only primary typing, I would probably go with Golbat and the Koffing line (maybe close with all the poison snakes and than there´s also Trubbish, which is usually so hated I must like it :) )
If I make some stupid grammar mistake, I´m terribly sorry and feel free to correct me.
Pure Poison: The Nido- family. They are a pretty different and good take on a poisonous animal, rather than your usual snakes and stinging bugs.
Primary Poison: I'm surprised there are so little. Toxicroak's line is pretty clever and original, it really is recognizable as it's own creature.
Secondary Poison: There are far too many, most being part grass and part bug... On the other hand, I generally dislike those type combinations. They seem just too simple to me. So, skimming over them:
Venusaur's line is great and probably of my favorites. Vileplume is good too.
Spinarak is adorable, and Ariados is cool, I guess.
Roserade is a great Grass type, and Scolipede manages to be good despite it just being another Bug/Poison