I moved here after over 7 years in Switzerland. I moved there because my husband was Swiss, and he didn't want to move to the US. I found Switzerland a difficult place to live, it is hard to make friends with locals, etc. and while I do speak the language, I'm not fluent and it was difficult.
I had travelled to the UK many times before I met my husband, and we started to take holidays in London, several times a year. We decided to move to the UK, as he was struggling to find work in Switzerland. He moved to London ahead of me, and a very, very long story short, I ended up in Manchester and we ended up splitting.
I've been in Manchester for just over 2 years now, and I can't imagine ever going back to the US. I love the history in the UK, which is all around us. Public transport, even at its worst in Manchester is far better than I ever experienced where I grew up in Cleveland, Ohio (very similar cities, really).
Then there's the cultural things. I prefer British TV. Their pragmatic view on things. The lack of overly boastful attitudes. Heck, even their take on patriotism here is much more to my liking (even after the patriotism binge for the Jubilee!). The way newspapers are still read and flourish here, despite other news sources. Books are still a very valued thing, a way of life, as is theatre and other arts. Things are far less superficial.
Even the music on mainstream radio doesn't feel as superficial - overall - there are some unexpected gems showing up all the time. Brits are not only unafraid of their musical history, but proud of it - including movements like punk, genres such as metal, etc., whereas in the US those types of things are frequently swept under the carpet or only the clean shiny stuff is showcased. Heck, BBC Radio 6 chose the month of the queen's jubilee to launch their month of Punk (where the Sex Pistols' anti-monarchy protest song was the feature), as did BBC 2 for their documentaries. One of the mainstays of Christmas music is Fairytale of New York - not the happy, jolly, singing snowmen stuff. You'd never see any of that in the US.
The Brits don't feel the need to be "cleaner" (meaning the squeaky-clean all-American image that really defines America to me) or shinier than everyone else. It is really hard to explain, I'm not sure anyone else sees it that way.
Hope that makes sense!