My Favorite type has to be Dark.
I don't know why! You may think that since my OC is Cleffa, I'd be into normal or fairy types! I really like the Purrlion line. Liepard is an amazing Pokemon and it's so beautiful! The contrast of the purple and yellow was so unexpected, but welcome. When I first bought Black, I neglected catching a Purrlion because I didn't want a two legged cat. However, I wish I did stick with Purrlion because instantly I wanted a Liepard as soon as I battled Team Plasma. To add on to that, Absol.....nope no more words. Absol is fabulous! As soon as I could catch one in Pokemon X, I did. I was so excited to find it's mega stone and forgot then forgot to find it until after I beat the elite four. When I battled my Rival in the final town, (with the battle Cheatu-?????) and he gave me the Absolnite as a reward, a just about gave myself a nosebleed with the facepalm.
My least Favorite type is Fighting
The humanoid Pokemon. With the exception of Meloetta (Pirouette), Keldeo and the Sword trio, I despise of all fighting types. I'll make it known that I love psychic types as much as I do dark. So I usually will a psychic or a dark on my team. Not until recently have I had a team without psychic types. So, fighting types have never been a huge issue for me, as I usually carried an Espeon, Meowstic, or a Giafarig (I don't think you guys understand how useful a Girafarig can be!). It's not that fighting types are hard to beat, they just look weird. The Timber line has veins popping out everywhere, the Sawk line looks too much like a human, I feel like Machoke is wearing less than he should, along with Machamp. Plus, there are female versions of these Pokemon, as it's just.....awkward. I really don't like human-like Pokemon, I feel like capturing a Sawk would be like capturing another human being. It just doesn't seem right to me.