I like 4minute, Big Bang, 2NE1, f(x) of course and Girl's Day as well. I'm not really into guy groups honestly, the only other one I like is Super Junior. Though I do kinda regret not knowing about TVXQ prior to splitting up.
Anyway in addition to those mentioned above I also like Girls' Generation, Dal shabet, After School, KARA, Brown Eyed Girls, A Pink, CHI CHI, miss A, Nine Muses, Rainbow, RaNia, Secret, SISTAR, T-ara annnnd Wonder Girls.
The solo artists I like are BoA, Lee Hyori, G.NA and Han Groo. Though I am starting to like NS Yoonji too.