I'm in a similar boat, though probably not as dire yet. I drove my little Mazda Protege off the lot in 1995. She's needing more and more work every year, but I'm trying to get another year or two out of her before I bid her farewell.

I'd say go for a smaller car like Fit. Yaris looks nice but isn't terribly well-thought out in terms of cargo and seating like Fit. You can go up to a Matrix, the seats go down flush, including the passenger seat, and is lined with plastic for easy clean up. Mileage is still good, and there should be plenty of used ones out there as they're really popular.

My next car is definitely going to be a hatch back.