London is my favorite city in the world.
I was mightily impressed with Manchester.
Bath is very charming.
Bristol is really starting to make a mark.
I keep having miserable times in Oxford, but that has nothing to do with the city...just clouds my vision.
Oban's gorgeous, and we'll be there again next month.
Sheffield's somewhat depressing, but it has a great dry ski slope.
Could go on, but these are just my random thoughts and experiences. But to answer your "living" question more specifically...if I were 30 years younger, I'd for sure start out my adult life living/working/breathing the city centre of London. Then I might move on to Manchester where I'd spend my 30s...just seems really great for culture and raising kids.
But in the end, I'm happy right here. Not a great place to visit, nothing special in terms of living conditions. It's the people. I've never been made more welcome in a community.