I've always thought that the drive to/from Valdez / Glennallen is one of the more scenic on the Alaska road system, particularly if the weather is good.
I don't know that the jaunt from Haines Junction would be a whole lot different than what you've seen / will see already.
The drive to Homer is long and, while it can be nice, it's usually only the last 60 miles (with the views across the inlet) that strike me as being scenic. Homer is a neat little town but (IMNSHO) a bit overhyped and can get a bit of a "tourist-trap" feel on the spit.