I went to Deep Creek Lake in Maryland a few years ago and love this as a nearby vacation spot. Just a few hours drive to Oakland Maryland and this is a nice alternative to the beach. If you have a big group, it would be worth it to rent one of the many vacation homes that are available year round to rent. It can be expensive, but if you get 12 people, the price isn't bad at all, and they often have fireplaces and hottubs. There are some hotels and B&Bs that are better suited for a couple. Lots of great water activities that you can do on the lake, rent boats or jetskis. There were also a few nearby wineries that were fun to visit on the way home.

If you are looking for a weekend away, I would strongly recommend Deep Creek Lake.