The pregens I've made for a showoff of FC are:
Pech Adventurer, Sage
Striking Human Aristocrat, Mage
Saurian Priest, Cleric (with as many of the Curse feats as possible)
Orc Criminal, Burglar
Ogre Gladiator, Captain (with a kobold lackey)
Goblin Druid, Lancer (wolf-rider with 2nd wolf)
Dwarf Guardian, Soldier
What I noticed:
The Captain, Lancer, and Soldier each stepped on each others toes in some way.
An Unborn Fencer was one idea I considered,
It's been when I've told people that Ents and Dragons (Rootwalkers and Drakes) are playable, that I've gotten the biggest reaction.
Just as a note, if you're designing (or modifying) an adventure for FC and have Large creatures common in your setting, door & hallways may need to be resized.