Does it count if I like them because of their looks and not their music? I'm not a fan of K-pop (or pop in general).
B1a4 (so cute and dorky), shinee, bigbang, ft island, super junior, btob, vixx, nu'est
CNBLUE, BTOB, and 2PM are my current favorites~ EXO was there, but as their comeback is delayed, my love for them is fading quickly..
B1A4, Suju, Miss A, 2NE1, EXO. And I'm liking B.A.P. pretty much too
Big Bang, SuperJunior, LeeSang(not sure they're Kpop), B.A.P, 2PM, ChAOS, WonderGirls, Rain, Kim Jong Kook.
SHINEE SHINEE SHINEE SHINEE SHINEE SHINEE SHINEE SHINEE SHINEE!

FT Island, CN Blue, C Clown, Juniel, Lunafly and Ailee
NU'EST is my one and only true love for now <3 but I really like U-KISS (I'm slowly becoming a Kissme) those are my Top#2 K-Pop groups. For girls I like Orange Caramel and SNDS. And solos I love Lee Seung Gi, Kim Tae Woo and Ailee.
IU, Infinite, Block B, and T-ara.
My fav K-POP Artist... BIG BANG!!! I'm Die-Hard VIP!! Hehe.. Love them sooo much.. They're awsome! <3 Other artists i like.. Well, all the artists of YG Family, and then, FT Island, Beast's Hyun Seung, Dongwoon, Gi Kwang and Doo Joon, Lee Seung Gi, IU, Kim Tae Hee, Joo Won, Dalmatian, Boyfriend, Alexander,... and some more!! :)
My current favorite K-Pop artist is Ailee. I've seen her on Dream High 2 and wasn't really impressed (and she didn't get much time on screen anyway now that I think about it again) but after checking her mini album I just loved it. Powerful voice, catchy music. Good luck to her in the future! Lately I'm also listening to Lee Seung Gi's songs. His voice is calming, but not very special. His music also gives the same effect. His newest hit "Return" is probably rather repetitive, but I'm caught with it as well. I can't really explain this part good, oh well. XD
Super Junior, SHINee, good impression of EXO but no final opinion yet, and though I like CNBlue, I love them when they perform live! One of the best groups when they perform live, maybe the best!