I love Myrtle Beach, while it IS touristy, and IS crowded during summer peak season, I've never once has a visit there that is trashy. It's like any other place where many people vacation and have built up - if you can enjoy the cheese tourist parts for entertainment sake, and the beach for is activity, it's a great place. My family, friends, and myself have always enjoyed ourselves in anything we have ever done down there both on the beach and the touristy strips. If you're looking for JUST beach, and not a crowded one I would say Top Sail, Island NC, the Outterbanks. etc.

As for how much there is to do in November, I wouldn't know. Charleston is fabulous with its shops and restaurants.