what little bit of Lake Havasu City I've seen was beautiful, and I wouldn't mind visiting more often, but I wouldn't live there. It gets too hot out in the desert, and the town is full of rich baby boomers who ALL DRIVE SUV's.
I mentioned on another message board that Flagstaff, Albuquerque, and Winston-Salem are beautiful cities, and I wouldn't mind living in any of those places. Kingman, AZ is also a nice little town, but again--desert. LA is a very beautiful city to go sightseeing in, just as long as you stay out of the trouble spots (i.e. half the freaking city)
Towns I could NEVER live in, no matter what--
Boston. I'm sorry, but the street patterns in that area are very confusing, and it's more Ghettoficated than East LA, not to mention that the majority of the people there are almost rediculously liberal--and this is coming from a Californian. Plus the taxes tend to be pretty high there. No wonder everybody crosses into New Hampshire to buy groceries (no sales tax, baby!).
Houston=SCARY. Nuff said.
NYC. Never been, and although I'd love to visit, I don't think I could handle living there. The city would eat me alive.
Detroit. Though it may be the Mecca for all car enthusiasts, well, refer to Houston and NYC.