Lost Universe Special is a one-book story featuring Kane and the Swordbreaker crew.
(Source: Kanzaka.wikia.com)

Young sorceress Lina Inverse and her dim-witted sidekick Gourry Gabriev travel through a somewhat medieval setting, doing good and fighting evil. Well, by "doing good and fighting evil" I mean "stealing from corrupt rich people and blowing things up".
The stories in this volume are occasional tie-ins to the novels and short stories.
(Source: Baka-Updates).

Lina Inverse, the precocious and dangerous sorceress, has teamed up with the barbaric and busty Naga the White Serpent. Together they fight demons, thieves and monsters...all in the name of treasure and a good meal. Join Lina and Naga in their latest tale of tribulations and triumph in a medieval world of monsters, mayhem and monkey business.
Adapted from the Slayers Special light novels.
(Source: Baka-Updates)

Kane Blueriver and Canal, his AI companion, are trouble contractors who take jobs which require their special skills. This could go from armed escort, to patrol, to capturing dangerous criminals. Milly is a private eye who has to be the best at everything (uchuu ichi!!). When the three of them get together, they run into one mess after another, gradually uncovering more of a mystery that ties the legendary Lost Ships to all of their pasts, bringing them closer and closer to a discovery that something called Nightmare would rather not have them find ...

(description taken from animenfo.com)

After meeting the enigmatic woman Hureika in a sideside village during her travels, the beautiful genius sorceress Lina Inverse’s fate takes a dramatic turn. Separated from her partner Gourry, she finds herself swept ashore onto an unfamiliar land. Faced with violent monsters, she is suddenly unable to wield her magic…. But her grand adventures only begin once she is saved by Lyos, a boy who claims himself to be the “Knight of the Aqua Lord”….

Alternate retelling of the Slayers TRY anime.

Having lost the Sword of Light in the previous battle, Lina and Gourry continue their journey in search of a replacement weapon. On the way, the two of them meet up with Amelia and Zelgadis in the kingdom of Luvinagard while taunting some pirates. Lina is happy to reunite with her old friends, but appearing before her is Luvinagard's Inspector of the Special Investigative Unit; a man called Wizer. However, Lina is amazed at his unusual behavior...

Lina Inverse, a wandering sorceress and bandit-killer, joins forces with roving swordsman Gourry Gabriev in what's supposed to be a quick union of convenience.

Adapted from Slayers main novels 1-8,
4th volume adapted from Slayers Return movie.

-- Manga Updates

After being shipwrecked on a remote southern island, Lina and Co. protect its townspeople from an attack by pirates…. But the island holds a deep, dark secret - and powerful magical forces are at work trying desperately to hide its past. The fate of the world once again rests in the hands of the over-bearing Lina Inverse… For better or worse!
(Source: Turtle Paradise)