Also there is another crossover gem(highlander/stargate), it's one of the best stories I ever read. It really captures stargate's essence of SG-1's characters and a good place for the newcomer to understand either of those shows. Here is the link and the author's name is Ecolea, titled "The Changing of the Guard". I have to warn you it is really long and promise you won't be disappointed!
http://www.seventh-dimension.org/
