The only place outside of the US I've been is Toronto. I liked it, but I don't know if I'd visit it again. Inside the US, I really like NYC, Chicago, and Boston and I've been to all three at least twice and still would like to visit each again. Southern Florida is also lovely, especially along the Gulf. Naples has some of the fluffiest sandy beaches, I love the sand there. Also the sunsets are zomg pretty.
On my wishlist are Germany, Switzerland, Japan, Paris, Madrid, Rome, Morocco, and Egypt (when it calms down) and seriously all of these places are because of the art, food, and culture. I also want to visit New Zealand, but if I do, I may build a hobbit house and never come back.