I had some time today, and remembered the wonderful EPA site for fuel economy. They've revised all their ratings for vehicles back to 1985 (although most of them are extrapolated, and not actually tested with the new methodology).
I put all of our vehicles in and verified the obvious: the MINI is tops! I'm actually averaging much higher than the site estimates, with my last tank running at 34.4mpg, and the one before it at 33mpg. I'd estimate that I'm averaging 33mpg for this year, with 31 or 32 / year prior to 2008 (I've started driving slower).
Actual miles / projected fuel usage / vehicle:
MINI Cooper (17000 miles / year @ 33mpg): 515.15 gallons @ $3.80 = $1957.58
Honda CR-V (~3500 miles / year @ 22mpg): 159.09 gallons @ $3.60 = $572.73
Total general fuel budget: 674.24 gallons, $2530.31
Racing (I pay for this outside of the family budget)
Ford F250 (~1800 miles / year @ 10mpg): 180 gallons @ $3.60 = $648.00
Mazda Miata (miles and mileage unknown): ~100 gallons @ $6.00 = $600.00
Total racing fuel budget: 280 gallons, $1248.00
Total Amos Family Fuel Budget: 954.24 gallons, $3778.31
All of this completely ignores external factors like repairs, general maintenance, insurance, payments (Amos family is loan-free!), titling, taxes, and other fees.
Interesting, especially as I start looking for new cars, I see that I can actually save $70 / year by getting a 2008 MINI Cooper S, but I'd spend almost an extra $900 / year fueling a MazdaSpeed 3.
If you're in the market for a new car, spend some time looking at that site!
By the way, there really was no point to this whole post.