Check out this thread for some claimed MPGs:
http://8thcivic.com/forums/showthread.php?t=11565
And yes, the Civic is good!
There have been some issues with the Civic that some people have problems with. If you're looking to get a Civic, wait for the 2007 models. Any first year issues should be resolved with the '07s.
And welcome to the forums! We hope you enjoy your stay.