1. The D&D Tactics Set
...To that end, not only will this box include dice and rules, but also a selection of miniatures (either completely original or just pulling from WizKids) including the most popular PC choices, plus a handful of classic D&D monsters (let's say skeletons and a beholder). Maybe include a medium-sized dry-erase battlemap with markers. With an original adventure, this would be a great purchase!
I'd think paper or cardboard stand-up minis for every creature in the adventure would be better than just a few plastic ones.