I think I asked a long time ago why America persists in playing games that no-one else seems to play (who plays baseball anyway?), is it so that they always have the winning team?

That's a good question, but I think the answer is that we do play the sports everyone else does, just not very well. Soccer is becoming more and more popular here (we just qualified for the next World Cup and have a "major" league now) and there is an American national Rugby team (two, actually - M and F) and I was once gobsmacked when I saw a bunch of blokes in cricket whites playing a match one Sunday afternoon at a local park here in Vermont (it's apparently a regular occurence, as I've seen it several times now).

I wonder what sport from other countries is routinely shown elsewere?

Well, here in the States we get very little foreign sports coverage, except for the "international" sports you mentioned: golf, tennis, Olympics. You can occasionally see an important European soccer match on one of the all-sports cable channels, and American soccer (and the World Cup) get national network coverage. I'd love to see rugby and cricket and things like that, but in the classic Catch-22 of the Television Age, only very popular things are on TV, and something can only become popular if it's on TV first. I once saw the Irish Hurling Championship (no, not what you think) on the all-sports channel late one night, and I wish they showed more of it (kind of like a combination between field hockey and lacrosse using cricket-bat-like sticks).

do you get horse races from Europe? I know that Nigel Mansell moved from Formula One to Indy car racing but I don't really know what an "Indy Car" is - is it a type of car or a type of circuit?

I don't think I've ever seen an international horse race (and nowadays the only American races on network TV are the Triple Crown). And based on my limited knowledge of car racing (a "sport" becoming more popular everyday here), "Indy" cars are a type of cars like F1 (maybe identical?) and there are two (I think) competing circuits of it. The more popular car racing here is "stock" car racing (but if I ever see one of those monsters at my local dealership I'll eat my hubcaps), also called NASCAR.