I like a lot of bug types and poison types, but other than that I would just go with my favorites. which incidentally does not include alot of Poison or Bug types...hmm.
Cubone (he wears a mask
Pideotto (Cool name, coolest looking of the birds)
Magnezone (They finally gave the Magnemite series some personallity and I'm into it.)
Lanturn ( Coolest fish, cute and useful)
Jumpluff (because he wasn't very strong but I could still status effect my way through the elite four in G/S)
Cyndaquil (First fire type I liked, cutest one to)
Tangela (used it once, it's kinda not good. But it looks cool. I'm not acknowledging the existence of its ugly evolution, whatever that was called.)
Wailord (It's cool because it's big)
Mareep (It's a sheep, a F'in SHEEP)
Ledian (It would be higher if I didn't try to use him once, only to find him utterly useless.)
Haunter (Coolest ghost type)
Turtwig (Honorary mention because he finally got me back to choosing grass types over fire types, something I hadn't done since the first game in the series)
And no, Bidoof is NOT
on my list anywhere, I just love to hate it.
Stupid stupid Bidoof.