Seven Chevrons of Nine?

This is a crossover with Star Trek:Voyager
Major spoilers for "In the Line of Duty" and "Tok'ra", minor for "Family". Set before Serpent's Song in the second season.
After an exploratory mission gone wrong, SG-1 meets the crew of Voyager; Seven of Nine becomes a host to an old friend of the team.

Silence After The Song

Spoilers for "Tok'ra", "Serpent's Song", general Season Two stuff.
After "Serpent's Song", Sam can't help but question herself about Martouf.

Memory's Betrayal

Spoilers for "Jolinar's Memories" and "Devil You Know".
Sequel to Silence After the Song.
After "Devil You Know", Sam is tormented by Jolinar's memories.

Following the Sorcerer

A rather involved story that has Sam and Martouf, surprises from Jolinar's past, and a few strange twists.
Spoilers for everything up until the start of season four; Major ones for Tok'ra I and II, and In the Line of Duty.

Chapter I
Chapter II
Chapter III
Chapter IV
Chapter V
Chapter VI
Chapter VII
Chapter VIII
Chapter IX
Chapter X

Written In Stone

Spoilers for everything up until Divide and Conquer; Major ones for Divide and Conquer, and In the Line of Duty. This is a direct continuation of FtS.

Chapter I