As much as I just hate civics as a matter of personal preference, I hate Mazda even more in terms of reliability. Probably the best indicator is the JD Power rankings, among hundreds of other articles and discussions out there:
http://www.jdpower.com/autos/Honda/Civic/2007
http://www.jdpower.com/autos/mazda/m...2007/hatchback
That having been said, Toyota still has the best quality out of any car company. In my line of work, I frequent car plants very much and have been in and out of GM, Honda and Toyota plants and can tell you that Toyota has the most stellar quality control you could imagine from an auto manufacturer. Honda is still very high up there, and from what I have heard honda makes the best engines. Between Honda and Mazda I would highly recommend the Honda. It really is a scenario of getting what you pay for in the long run.