I've had my Fit for 6 months, and have really enjoyed driving it and have had no problems with it. I do a combination of city/highway driving and average 36- 37 mpg overall. I have the Sport package which overall has a great look and is fun to drive. I did purchase floor mats, body side moldings, and window tint after market (see below re:improvements). As others have stated, the upholstery attracts fuzz, so I carry a lint roller in the car.
Ridiculous amount and flexibility of the cargo space, Ipod dock and sound system, super easy to park
Change fabric to something that is not a dirt/fuzz magnet,add armrest on front passenger side, add standard body side moldings (to prevent door dings), add standard window tint and floor mats