I wouldn't go any less than 4" of asphalt put down in 2 lifts. Anything less will break up with freeze/thaw and traffic. That is the complaint about these door to door/flybynight asphalt companies only putting down 2" with little or no subbase preparation or fill and then you never see them again. 5" or 6" would be better depending upon if you stay parked on it or have any heavy vehicles. Talk to your local asphalt company. Most store parking lots have at least 4" and more in the traveled portion and those don't always hold up over time when you get too much weight on them along with moisture and freeze/thaw. We all drive through store parking lots with unfixed potholes. It isn't cheap, its a lot of work cutting it out, and it doesn't look good to have patched potholes in your drive except that then you do need a chip seal to cover it up.
Our city is looking at establishing parking lot standards because developers pinch pennies on their parking lots and then end up leaving a lot that deteoriates into an eyesore that the store owners and renters can't afford to fix.
I would go with 4" of asphalt and 4" of compacted gravel subbase as a "bare" minimum depending upon your soil type and its compaction rate before doing a 2" Asphalt and 6" of gravel(sorry Jay). For example we have a lot of clay around here which compacts well so people avoid much subbase but clay also heaves a lot which then requires a gravel subbase(usually an AB3 rated gravel). A 4"A (2" of asphalt base and 2" of asphalt top coat(They are a different mix))and 6"G would make a long lasting drive and is my recommendation. Otherwise up to 10" of subbase is all the better but maybe not necessary for a normal driveway.
Jay is right though that the job starts from the ground up and without proper compaction and drainage, water will always get under the asphalt and freeze in the winter. It still hasn't been perfected on highways yet. I used to be a heavy equipment operator for a road construction company and operated a paver among other things. There was always somebody who wanted a "budget" driveway but we knew it wouldn't last.
Talk to your local asphalt companies and get some recommendations and quotes. Ask about the life and what written guarantee they would give. Also get some quotes for concrete from some concrete contractors. More and more the prices are getting comparable. good luck.