There are so many places I would like to go that I thought about restricting myself to a top ten, but that proved to be too difficult, so instead I will try and be brief.
I would love to visit all 50 states, so far I've only covered 12. I don't count them if I've only driven through, or had a layover there. However, I am having a bit of trouble thinking of specifically where to go in each state. Once again the trip must be more than fleeting.
I'd also like to visit D.C. and do the whole touristy bit. I grew up in Northern Virginia and I sort of took the place for granted.
Canada! I'd love to visit Prince Edward Island (oh the thrill I got when as a child I discovered that the setting of Anne of Green Gables was a real place), Quebec (especially the Old Town), Victoria (my sister went there for her honeymoon and it's beautiful) and there is this marvelous cross-country train trip that I day dream about from time to time. I don't think our neighbor to the north gets enough interest.
Europe: my list is jam packed! Iceland, Ireland, The Netherlands, Germany, Denmark, Spain, Italy, Greece, Slovakia, Czech Republic, Hungary, Austria, and Switzerland are all on my list. I've been lucky enough to visit France and the UK already, and while I would love to return to those places and see the things I didn't get a chance to see (and there are many), I would also love to increase my list of visited countries.
New Zealand and Australia also rate highly, but the airfare alone is cost prohibitive. In truth, I think I would want to see New Zealand more than Australia, mainly because of the sheer number of things that live in Australia that can kill you. Check out the locales of the deadliest snakes and spiders and see how many in the top ten live there! Not to mention poisonous coral and jellyfish, as well as assorted other examples of wildlife that can seriously wound or kill you. Read In a Sunburned Country by Bill Bryson if you don't believe me.
Barbados, Bermuda, Puerto Rico. I'm not as keen on the Carribbean nations for some reason. Maybe because I sunburn. Maybe because of hurricanes. I don't know.
If I was braver I'd also include China, Russia, Egypt, Brazil, Peru, and South Africa on my list. I guess they are on the list, just farther down the line of possibilities. Now, if I could teleport in and see what I wanted to see and then teleport out that would be another story.