There's a small stand near CGV located right by the Exit 3 of Apgujeong Station. It's behind McDonald's and you can locate it by the smell of the grilling. It's name is simple: Apgujeong Ddak Kkochi (압구정 닭꼬치)
There are two kinds of chicken skewers: gochujang-marinated and soy-sauce-marinated. I had asked if the gochujang-marinated was really spicy, and he had said just to be safe it'd be best to stick with the soy-sauce based ones for those that can't handle spicy. But if you're like me and can handle the hot sauces of "King Taco", you can definitely handle the spiciness of the gochujang skewers.
After you pick your choice of chicken skewer he grills it on the spot for you after brushing on the marinade.
The skewers are priced at ₩2,500 each for either marinade.
It's a simple arrangement with chicken and green onion in between each bite, but definitely popular for its consistent taste and reasonable price.