I went to 明洞景福宮食烤牛肉, 炭火燒,service is good. 冷面好食. 2大1小, 叫一份雜牛肉(66,000) + 冷面+drink, 無黑面. Visa can enjoy 10% discount on beef menu. Make reservation is better since I need to wait around 20 min for seat. A lot of Japanese go there.
U can get some information from Tourist information counter, some travel information books with some discount coupon, and I got visa card discount book in Jamsil station which list out all discount shop including dinning, shopping etc.
買雪花秀 in Lotte duty free shop in Jamsil, visa platinum can enjoy 10% discount.