I highly recommend it! Everyone should go see an Olympic event(s) live and in person at least once if they can.
My wife and I went to both of the gold medal matches for field hockey. This was my first summer Olympic games to attend and there is quite a bit of difference between summer games and winter games (went to Vancouver). Overall I enjoy winter sports better but there is something very cool about the summer games with the greater amount of games, competitors, and more events located together. The Olympic park was huge and teaming with people most of the time. Overall I give London a thumbs up for their hosting. Security wasn't too bad and while expensive, I didn't think that the cost was quite as staggering as it was in Vancouver. As an FYI to anyone thinking of attending in the future, in my experience from the Vancouver and London games, the ticket cost, while quite high, is actually the cheap part. It the hotels, food, and travel are where the real expense is.
Now I will be waiting for the ticket lottery to open up for the Soshi games in about another year.....