I would like to pick two destinations (Phoenix to Vegas, for instance, or Phoenix to Johnson Valley, etc...) and drive the entire distance entirely off road (or at the very least, on nothing but back-roads and forrest roads... nothing paved if at all possible). Don't care where to where, honestly. (Basically this that Avis posted: "I gotta try and find the name of the road, but I remember a trip report of a couple taking dirt from the Canadian border in Montana, all the way down to the gulf coast. Only time they hit aspalht was at the border crossing into Mexico." but in a more manageable chunk.)
Going back to Baja and driving the entire peninsula myself, not just as co-dawg would be awesome.
Moab time is always good, but the laid back Colorado trip is something I'm yearning for again.
The Rubicon is a "meh" for me, honestly, but I'd like to check it off the bucket list.
Most everything else has to do with a lot of travel (South America, Central America, parts of Europe, etc...).
Of course, at this point, I'd like to just go run all the trails at Bumble Bee without pulling cable. LOL.