I've been watching, right now Spain (with Rafa Nadal) is playing tennis, since he's the best tennis player right now I guess we will win the gold medal. Spain has won one gold medal, in cycling, and a bronze medal so far. In basketball we're supposed to win the gold medal too.
I am not really into sports, but I love those sports that have to do with water, so I try to watch swimming, and especially synchronized swimming (don't know when it will take place though). Oh and gymnastics, I love that too
PS: The opening was awesome! I didn't watch the whole opening though!