When I posted my Against the Giants army lists for Hordes of the Things, I mentioned they needed an opposing army comprised of your standard Dungeons & Dragons adventuring party.
One person on the HotT mailing list suggested the original characters from the original Lake Geneva campaign (Mordenkainen, Robilar, Tenser, et al.). Another player suggested two heroes, a magician, shooters (elven archers) and blades (dwarven warriors), and someone else came up with magician, cleric, sneaker, shooters, knights, and warband.
Here's my own take on an adventuring party for Hordes of the Things, based on the high-level D&D characters that would take on the giants:
Lord & henchman Hero General 4
Wizard & familiar Magician 4
High Priest & acolytes Cleric 3
Master Thief Lurker 1
Ranger Lord & bear Warband 2
Lord's troops Knights x 2 4
Summoned djinn or elemental Flyer 2
High Priest's followers Spears x 2 4
Of course, after the giants are vanquished, the party can begin its Descent into the Depths of the Earth ...