If you are going to do it. Do it right. As others mentioned you should take the first shuttle bus in the morning to Wonder Lake. And keep your eye out for wildlife. It is up to the passengers to spot the wildlife. I have taken many shuttle bus rides and am amazed at the people that rely on someone else to spot the animals for them. They are also the ones that complain they don't see very much.
As an alternative, take the shuttle bus in until you see a grizzly bear - then ask the driver to let you off (the driver will not let you off near the bear but after another mile or two). Then go for a 2 mile hike or just find a nice spot away from the road to sit and be quiet - then come back to the road and get on another bus.
It is true that some drivers are not as entertaining recently since they are now employees of Aramark corporation and not the National Parks. Aramark also has the concession for the pricey tours so it is no surprise they are trying to encourage people to be "entertained" on the tours with lies and fantasy stories.
If you have a quiet driver - ask them questions and they may open up.
Definately bring binoculars 10 X 50.
"Whenever you find that you are on the side of the majority, it is time to reform."
Mark Twain
Here's the link to the Park Service web site that explains the two types of transportation within the park. Park Transportation
We've taken the shuttle buses on our two visits to Denali. They are much cheaper and you go the same places and receive substantially the same narrative. Both stop when game is sighted and both use the same type buses. In fact, we have a friend who drives one of the tour buses in the summer. The way she got the job was because of her experience driving one of the shuttle buses. She says don't waste your money by taking a tour when you can see the same sights and game on a shuttle bus.
Allegro 32 BA
Jeep Liberty Toad
Buster, 3 lb. Yorkie
I've only done the shuttle bus (3 times). I really can't think of what I'd gain by taking the 'tour' bus. Each of the drivers was quite knowledgable and generally spotted animals before the passengers.
To make sure you see animals, write ahead and get their schedules. Oh, wait...
Oh, and its not strictly true that no private vehicles can drive the road. I believe that if you book your stay at Kantishna, you get a road permit for your car. That may only be in the 'shoulder' season.
Andy Tejral
Anchorage, AK
2000 Tacoma 4-banger
2003 Chalet Aspen