Lina Inverse and her partner Naga the Serpent take on a variety of jobs for quick cash, food, and/or their own skins:

The Scary Chimera Plan — Pits Lina and Naga against a lunatic magician who intends to use Lina to create a fearsome, spell-slinging monster.

Jeffry's Knighthood — They are hired by an overprotective mother to see that her son — a young man barely capable of holding a sword — becomes a respected knight, by "helping" him fight off the marauding soldiers terrorizing the area.

Mirror, Mirror — Puts the two in a race to hunt down and capture (for bounty, of course) a rogue sorcerer who has found an ancient artefact that can create loyal duplicates of anything or anyone, including his enemies.

Source: ANN

AniDB | ANN | AnimeNfo | MAL | TVDB

Sequel: Slayers
Sequel: Gekijouban Slayers
Prequel: Slayers Excellent