List of samples:
(Note: This library is intended for use in games, and sample texts are interpreted as such.)

norse - Ancient norse names.
norsemyth - Names from Norse myth. Also good dwarven names.
odin - More than 200 different names for Odin, again, dwarven stuff.
beowulf - Characters from the epic Beowulf, different norse variations.

hebrew - Ancient Hebrew names. May inspire deities and divine beings.
roman - Names used throughout the Roman Empire.
celticmyth - Names from Celtic lore, also good for a fantasy setting.

saxon - Ancient names from Brittany, may use in Arthurian settings.
welsh - Ancient Welsh names, perhaps also fitting for Arthurian legends.
elven - Selected names from the Welsh text, somehow they really sound like the names of elves.

lusiadas - Classical Portuguese epic text, very big, a nice stress test. Smooth sounding names.
russian,
polish,
greek,
japanese - Modern names in different languages, setting-dependant. Samurai, Spartans?


Sample sources:
www.wikipedia.org