Last adventure our party (of five, including one cleric and two Dragonborn) had to escape a house getting swarmed with zombies. In an epic escape (much like Night of the Dead), the characters bull rushed through mobs and mobs of zombie minions until they reached the road, which for some unexplained reason, was undead proof...took them a bit too long to figure that one out.
I think the zombie horde was probably one of the most challenging encounters for the players...and probably most exciting...as they faced tide after tide of undead...and for each one they took down, another another one took their place from the edge of the battlemat.
I'm guessing they must have killed well over twenty, but that wasn't the point...it was more of a puzzle that the party needed to figure out. Heh. They lived...
The encounter right after, they decided to "sprint" past the zombies...heh.
Fox