In the same exact situation, we bought my daughter a Mazda3 a year ago. The car has performed perfectly. Great build quality, fun to drive and enormously practical. I "borrow" my daughters car all the time.
If we were to make the decision again, we'd still get the Mazda3. I'm very satisfied.
Link to an old thread:
http://forums.pelicanparts.com/off-topic-discussions/426355-poll-car-would-you-buy-under-20-000-a.html