What area to stay in Seoul.

Actually, Itaewon has recently become somewhat hip again among Koreans as there have been many nice restaurants and hot clubs (e.g.Volume) opening up. The alley right behind the main road of Itaewon is now dubbed as the new 'gourmet restaurant row'. So as long as you are in the right street, it is not so sleazy even at night. Also quite a gay scene there I hear.

Also quite a gay scene there I hear.

Absolutely. 'Homo Hill' as it's known, which is parallel to "Hooker Hill' is absolutely buzzing every Friday and Saturday. Crowds of people spilling out of all the bars and stuff. It's a really cool night actually, even if you're not gay.