Fishing gear. I find the same gear that is useable for bass fishing here in Florida works well for Alaska and Canada. If a person is going to target halibut, the of course you need heavier gear but most visitors will go out on charters where they furnish all the gear needed, the same with most king salmon charters.
I like to fly fish so have some heavy weight, 9-10 weight rods, lines and appropriate reels. My fly rods all get to ride in metal cases for protection from the trip but I keep a couple of set ups on the back of the rear seat, one a casting rod and reel and a spinning rod and reel. 20 lb power pro Kevlar type synthetic line on both. I like Ugly Stick rods and Shimano reels on both. Nice quality gear but not nice enough to cry over if I slam a door on one or drop it in the water and watch it disappear. If I ever broke one of my custom made fly rods, I would probably have to seek therapy to get over it. LOL
Alaska has some of the most complicated regs of anywhere I have ever fished, so get a copy of them, available at any sporting goods place, and read up on the area where you want to fish. Good info is available at
www.alaskaoutdoorjournal.com for fish runs, etc. Most sporting goods shops can give good local information as to lures, flies, gear, etc.
Alaska and Yukon have a reciprocity agreement for residents of both, in that if you have a license from one, you are allowed to buy a resident license in the other. All Canadian provinces have their individual licenses, the same as the different states. When we were living in Alaska and traveling out of there in the summers, I would often have besides my Alaska license, one from Yukon, BC, Alberta and perhaps a few lower 48 states.
Many of the attractive spots along the highway have been over fished, IMHO, so often it is necessary to walk a 1/4 mile up or down stream. Now if a salmon run is in progress, you find a spot and wait for the fish to swim to you.
On edit: here is a thread where a bunch of us were lying, I mean talking about fishing in Alaska, back a few months. LOL Might be something worthwhile in some of the comments.
http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/27470673/gotomsg/27470867.cfm#27470867