Thinking on this for a while, I think a set of "dungeon adventurers" would be well suited to a sprue layout similar in idea to WGF's Apocalypse Survivor sprues.
Instead of sprues with an eye to creating rank and file troops, these sprues would be designed with an eye towards character construction.
It would be a great way to customize the minis to match players concepts of what their characters look like. An assortment of heads, differently armoured bodies,weapon arms, and other assorted equipment and loose weapons would make it easy to give your mini the look you want.
You could start with humans and follow up with adventuring kits for typical fantasy races.
Other follow up kits could be a set of henchmen with options for carrying torches, lanterns, treasure chests, and other supplies. You could even throw in a packmule.
Possibly even a kit for making mounted versions of ones characters.