I haven't seen a whole lot of big changes in the last few years (at least not any backed by solid testing/data - that I'm aware of).

First thing is to check if there are any sealants disallowed by your rim or tire manufacturer.

As far as your desire for longevity - in my experience, most of the latex-based sealants perform pretty similarly. Orange Seal has an "Endurance" version, but I don't know that it lasts any longer than other brands like Stan's (my understanding is that the original Orange Seal dried out more quickly than most sealants... hence the introduction of 'Endurance').

Personally, I've pretty much landed back at Stan's. It's the original standard, and they've improved it over the years. It's relatively inexpensive and easy to find. I also pretty much only buy the single serve sealed bottles now, because I don't use enough sealant to warrant the big jugs (which will spoil/solidify over time on the shelf... even if unopened/sealed). It's better to buy smaller quantities more frequently. So, this could also nod towards using whatever your local bike shop sells and turns over frequently.