SG1 and DS9 would be a weird crossover.
You have the humans of the enlightened future meeting a team of military personnel from the past, lead by a man who tries to avoid enlightenment whenever possible. He'd probably end up in Quark's playing darts.
Carter is going to immediately frustrate any attempts to limit damage to the timeline (not that it makes sense given that they'd have to be from a parallel reality) or invoke the prime directive. She's going to be full of questions, and she knows enough about advanced alien technology that she'll probably be able to figure out more than they'd want just from observation. She'd also probably figure out how to use the wormhole to get back home, being something of an expert on the topic.
Daniel is going to have the unique experience of being an archeologist that is now a relic of the past. Not much for him to do as a linguist since they have universal translators, though it would be funny if they brought it up and he thought they had all just been speaking English, since everyone in their galaxy does for some reason. It'd also be funny for him to be recognized by the prophets or Q, as though they knew him from his brief period as a vorlon or whatever.
I think Dax and Teal'c would hit it off, they have so much in common.
And things would get very confusing if someone activated an emh.
Also probably for the best that the Atlantis team isn't there, as O'Brien would have some awkward questions to answer. Besides, they're already too busy crossing over with Enterprise and answering their own awkward questions about Tripp.
Oh, and I really hope Jellico is visiting the station.
