This one is easy for me. Growing up in the 60's as a science geek, where else... SPACE
Think about it. Weightless, seeing the Earth from way up, and the stars as clear as clear can be.
A bit harder. I think Italy. Venice. Milan. Florence. The birth place of the Renaissance. I'd probably even find time to get to Rome.
The British Isles. England. Scotland. Wales. Ireland. I'd make time to get north enough (over in Europe) during the summer to see the midnight sun, and try to see the Aurora as well (both of these are on my "bucket list"). Lots of time in London. And a trip to Stonehenge.
Half Your Life
Anywhere that's with my wife. Maybe a cop-out, but that's the simple truth. If you want a place, read my blog from Sunday for why it's San Diego.
I'm supposed to tag three others, but I'm new enough to the blogosphere that instead I'll do this... If you read this (and there are not three comments saying done), then "tag you're it". After putting yours in, come back and comment tothat effect.