Dawson City was an interesting place. The ferry ride across the Yukon is short, but fun. We also enjoyed the historical museums and the Jack London and Robert Service cabins. And make sure you take the time to drive to the top of Midnight Dome--the 360 degree views are spectacular on a clear morning, like being in a helicopter without the noise.
The best thing about the TOTW Highway is getting to see completely different scenery than you saw driving up the Alaska Highway. You are up on a ridge and can see much farther than along that section of the Alaska Highway. Even the North Klondike Highway was interesting compared to returning the same way we went north. And cutting out the frost heaved pavement and long construction zones west of Destruction Bay on the AH made the flat tires on the TOTW Highway a minor inconvenience!