Depending on where you travel, I think right now the best permits to have are AZ, UT, FL, with AZ and UT being somewhat of a tie, depending on where you're going. I used to rank FL higher, but that permit is being denied in more states over the last few years. For instance, it used to be good in WA, but now is not (whether resident or non-resident), while UT, which was always denied in WA, is now good there.
Though I have all three, I'm likely dropping Fl when it comes up for renewal. Right now the only thing FL gives me that the others do not is FL, and it's the most expensive of the bunch. Decision subject to change based on reciprocity changes in two years when I have to renew.
As far as resident permits, AZ* and UT residents seem to be able to carry in more states than anyone else.
*AZ does not distinguish between resident and non-resident for the purposes of permit issue, but other states (at least according to USACarry) make the distinction.