I love doing the whole "What can you fit in the Fit?" game.
Pretty much anything you want, within the length limit of the car. I've done:
Lazy Boy
Dresser
Kitchen stove
300 ft rolls of farm fencing
4 hay bales (laid a tarp down first for less mess, hay is like velcro on the carpet)
up to 300 lb of feed sacks from the farm store, multiple times a month
The buzzy gearing isn't a problem below 50 mph, which is 95% of my driving.