Travel Recommendations

I am looking for some travel recommendations. Andrew has never really travelled. He went to Florida as a child many years ago and recently went to Georgia just for work. Besides that he has never been on a real vacation. I want to take him somewhere but I don't know where. I'm afraid that going to a resort we will get bored a couple days in. The last time I went to a resort the only reason we didn't get bored was because I was in a bridal party and had a lot to do and we went sight seeing one of the days. Anyway.. I don't want it to be super expensive but still nice. Part of me was thinking a cruise but they can get pricey especially because we would have to fly to wherever they're porting from.. a resort sounds like a good idea but at the same time is it? Besides that I am open to travelling to places even in the US or wherever that have fun things to do. Las Vegas is on my list but waiting until December or early next year after I turn 21.