Focus reliability based on the ones I own:
2000: Expected 1st production year problems you'll see on the forum. Bought used 6 years ago. Replaced two power window regulators, ignition key cylinder and the plastic piece near the thermostat. Maintenance has been oil, tranny, plugs and replaced all the belts/hoses years back. Car has over 130k miles.
2005: My current ride and bought as the 2nd owner 3 years ago. Maintenance has been oil, tranny, plugs and replaced all cooling hoses last summer. Car has 83k miles.
2007: Totaled on a cow in Dec 2009. Regular maintenance and I had 60k miles.
2009: Was mine but gave to daughter for college commute. Regular maintenance and it has 47k miles.
Compare those against the 2010 GMC SUV the spouse drives. It was in the shop a few months back due to oil starvation caused by a blocked oil port in the head. Not impressed.
In the driveway...11 M2 (mine), 09 Focus (daughter), 02 Miata (my toy), 10 GMC SUV (spouse), 00 Focus (son)