Late Model (2008+) Ford Escape w/ 4 cyl and automatic. Easy room for 2 sets of doubles, Deco bottles, and gear for two technical divers. Gets 25-26 mpg regardless of whether you are tooling down the interstate at 70+ or driving in town.
Sits up higher than small station wagons so better visibility. Good room for 4 people if you aren't hauling dive gear.
Keypad entry on the door. Never have to worry about what to do with your keys, you can just lock them up in the car. Best invention ever for divers. All three of my Fords have this and I love it.
Relatively inexpensive, comapred to other small SUV's. You can get bran new 2011's for under $20K.
Personally, I like this way better than a pickup, which is what I used before. Main reason is that I can set up all my gear the night before and leave it safely in the car, as opposed to assembling everything when I arive at the dive site. Obviously, if you have a locking cover on your truck bed, you can still do this, but I use my truck for hauling large loads (and gooseneck trailers) so a locking bed cover is not feasible.
Only downsides I noticed in the last 2 years of ownership are that the factory Continental tires are really noisy after ~ 30K miles of wear. It's also not a Mustang GT in regards to acceleration, but it's not a Smart car either. You can always get the V6 if you think its too slow, but your mileage will onl be about 20 mpg or slightly less.
John