Air travel wise, I just want to experience as many different premium cabins as possible.
But one thing that I've been itching to do for years is to take a long and slow drive across the continental US. I've driven from Michigan to California once, but I was in a hurry and wasn't able to stop and look around to see all the interesting things along the way. Unfortunately my schedule is really busy so it's difficult to take the 2-3 weeks necessary for an adventure like this. :-(