I'm sorry to tell you that most Americans /don't/ think of British politics. Most people here wouldn't know who David Cameron is.
A lot of us seems to be obsessed with the Royals, however. In fact, a lot of American families (especially ones that aren't particularly well-off) like to talk about their noble heritage, and how if enough people in England all die at the same time, then Cousin Jim-Bob gets to be Earl of Frothingsloshe or something.
Speaking as someone who does occasionally listen to the BBC World Service, though, I wonder how different things would be if we did our elections for congress the way you do your elections for the House of Commons: no primaries, just one election day, and whoever gets the most votes gets in.
I think your Parliament is a lot more interesting to watch in session than either house of our Congress.
I'm also intrigued by the idea of the Life Peer. If I understand it correctly, when someone does something awesome for the country, the Queen can give them a seat in the House of Lords for life, but it doesn't pass down to their descendants.
Neat idea. Better than inherited wealth making someone powerful.