Yay! New story from Vathara! Upon a Fiery Steed is a Stargate/Gundam Wing crossover. This is an action/adventure story with only a smidge of angst, and some mild yaoi between Trowa and Quatre. I've only seen a couple of episodes of Gundam Wing, so I don't know very much about those characters. The Stargate team, however, are spot on. Daniel is captured by a previously unknown Goa'uld queen, but he's not the only prisoner. Duo Maxwell has also been caught, and he manages to help Daniel escape. But not, unfortunately, before Daniel is infected with the nasty Reaver virus that will turn him into a nasty and deadly creature that will only follow the orders of the Goa'uld queen. Needless to say, drastic measures are taken to save Daniel, and then the SGC and the Sanq government enter talks to form an alliance. There's a great scene in the story where SG-1 and Weapon Zero team up to prank the Tok'ra, who are, per usual, being total prats.
Changing of the Guard by Ecolea is a Stargate/Highlander crossover that mainly focuses on the characters of Methos and Col. Jack O'Neill. The series is pretty long, but very entertaining. The author does a good job of capturing the essences of these two characters as they form a strong bond of friendship. Methos discovers someone who accepts him as he is--no recriminations about his somewhat bloody past, and Jack is elated to find a fellow warrior that he can trust at his back and not have to worry so much about him getting killed. It all begins when Daniel is injured during a mission and recommends Adam Pierson to get started on some translations while he is recuperating. Unaware that the position has been offered by the Air Force, Adam (Methos) is expecting it to be something of a paid vacation. He gets much more than he bargained for when the Air Force discovers that he is Immortal.