I would say Las Vegas. I've been to the Grand Canyon a few times, and it wasn't that exciting...

I've also been to Disney World, when I was in second grade, and it wasn't fun either. I was TOO little to do anything, and you probably wouldn't have any fun, since you aren't a little kid (unless you have kids).

I've been to Las Vegas twice. I was actually just there about 3 weeks ago. I love it there. There is always something going on. I would suggest going there to ANYONE because there is a lot to do and see.