Hm. Korean media is doing it, so why don't I? The first half of 2012 is over and my vote for the top K-pop girl group release for the first six months is going to Sistar's "Alone":
Mind you, until this song, I haven't been a huge fan of Sistar. I've recognized their quality in previous releases, but there was always some element in their songs that prevented me from being completely hooked.
I got hooked to this song from the start, starting from the minor key and the sexy groove once it kicks in, but then the verse sections are quite good and the bridge and choruses are incredible.
Sistar are kinda known for being an overtly sexy group (and they've complained about that image, but then they should tell their choreographers not to make it a requirement for them to bend over like pin-ups in every friggin' video and dance routine they do), but I think in this song, sexiness is in the songwriting. The song is inherently sexy and whatever dressing or choreography is placed on it will be sexy. And they bend over like pin-ups quite a bit.
Runners up I would give to Miss A's January release "Touch" and Wonder Girls' fun June release "Like This" (both written and produced by Park Jin Young (JYP), on whom I have a man-crush because he seems to be some kind of genius to me). "Touch" has a great groove start to finish:
"Like This" is just a fun romp with fun choreography:
As for JYP himself, aside from being the CEO of the agency to which miss A and Wonder Girls belong and a producer and songwriter, he's also an artist and he did release a song in the first half of 2012 and promote it. And I must say that as few male pop artists there are that I'm willing to watch while they wiggle their bums, JYP has the moves and charisma that make me watch in a way that only Michael Jackson has otherwise compelled me. Seriously, he may not be physically attractive, but he has serious charisma:
I'll also give a nod to SNSD's first sub-unit, the 3-member TaeTiSeo's (Taeyeon-Tiffany-Seohyun) release "Twinkle". It's great funk/soul song written by an American composer/Korean lyricist. I think I'm not giving it the credit it deserves because expectations are always high for SNSD, and so when they meet those expectations, it feels par for the course even if it's a great track. The 3 singers, I don't think I'm going too far out on a limb saying, are among the four best (along with Jessica) in SNSD.
Finally, I note the debut of rookie group Spica in the first half of 2012 because it's simply the best and most mature debut of a girl group I've seen thus far in terms of quality. As a group, they may have some of the best vocals in the industry, up there in the range of Brown Eyed Girls.
I think the idea behind the group was to have good vocals, and the main vocalist, I gather, is a professional singer who has been recording the guide vocals for producers for years (after hearing her demonstrate some songs by other groups she provided the guides for, I'm convinced the producers kept it in on many of the chorus parts of the final mixes). Also, from what I can tell, they're the only group I've seen handle harmonies live. With other groups, I've rarely been convinced harmonies were being sung live.