If money/time was no object, I'd take a horse, hands down. But since I don't want to spend the money or time on a horse, I have a GMC Tracker. It can fit down pretty tight trails, and I can (and did) fold down the rear seats, throw a deer in the back, and haul it out of the woods. It's more versatile than a Jeep, and can go almost as many places as a quad, if I want it to.
I also have a DR650 street-and-trail bike that I've done a fair bit of hunting trips on. Street and trail bikes are great at some things - they can go 95% of the places a quad can, and you can get there without having to use a trailer - but if you shoot something big (moose, deer, bear) you have to go back and get a truck to haul it, and it's also a pain in the backside to haul a long gun on a motorcycle without breaking it down, which makes it pretty much impossible to get a shot off in a hurry.
I think the best vehicle would be a Suzuki Samurai. It can carry all the gas you need, fit in a 4-wheeler trail, and doesn't need to be trailered.