Central Festival and Maya are both awesome. CentralPlaza by the airport is pretty nice. Promenada is also nice, but a bit quiet and far away from everything. I think KSK is the only one I would call old and falling apart, but it's not so bad. I think it has character. It's definitely the weirdest and hugest brick building I've ever seen. I like all the strange empty spaces and hallways, and the bowling alley tucked away in the corner.

EDIT: Haha whaaaaat, I must have been to KSK 50 times and I never knew it had this huge theater [1]. I feel like I discover something new every time I wander around this place.

[1] http://www.topchiangmai.com/wp-content/uploads/2016/10/%E0%B...