Hmm... Going by the types that I seem to enjoy the most, mine is probably:
1. Ground - As most already know, I'm a total EQ-whore. Anything that can give it STAB is a-ok in my books.
2. Fire - I loved how someone at Bulba described the 'creation of a Fire-type'. You just take an animal and set it on fire!
Anyways, I always like having a Fire-type around. It's a cool element even without Pokemon influences, it's useful in-game, and a lot of my favourite Pokemon are Fire-types for one reason or another. Can't say I'm all that impressed with fat ol' Moltres or Ho-oh, tho... might be after I roast them >=)
3. Bug - I don't know why, but I love powerful Bug Pokemon and just the type in general. Maybe it's the fact that they can annihilate Psychics, of which I still hold deep, sub-conscious resentment towards from first generation. Or maybe it's just because bugs are cool critters in both the games and RL ^^
4. Fighting - Sorry... This is my last. Anyways, I gained a fond appreciation for all Fighting Pokemon and the type itself from 2nd gen on due to their increase in usefulness. Not only were two types added in which they're super effective against, they also received a lot of good moves... or simply just convenient moves. Brick Break is great to throw on a Pokemon if you don't know what else to do with it. Thank FR/LG for allowing you to buy it ^^
See... I'd put down Dragon, Dark, and Ghost, but I like the Pokemon themselves more than the Type. Grass, Electric, Flying, and Rock, etc. I like using, and Raichu is my favourite Pokemon, but I don't care for the types anymore than the rest of 'em. Water, Steel, Poison in particular... They're just kind of there. I don't know why I don't love Water-types more because I tend to use them. Steel types (and Psychics too) I just barely ever train. As for Posion... I think this gen may see a change with the amount of usage they get from me. Generally in the past I didn't touch them, though I tried testing out quite a few 3rd gen (and I