(I've had this answer ready for sometime, it's just that RL has been being *real*.)
I'm presuming the question means two canons colliding, not shifting characters from one over to another.
Star Trek's set up allows for so many cross-overs because they're 'seeking out new worlds and new civilisations' so they can run into people.
And lots of other sci-fi shows are full of people running away from things.
The obvious show to cross over would be Blake's 7, just for the look of sheer disbelief on Blake or Avon's face when a Federation captain goes, 'the Federation are friendly'. Yes, precisely *that* look. I suspect that Mal Reynolds's look would be similar.
Or possibly Crichton et al wormholing into Star Trek and really liking it but having to go back to their 'verse to stop Scorpius.
( Other Days )
I'm presuming the question means two canons colliding, not shifting characters from one over to another.
Star Trek's set up allows for so many cross-overs because they're 'seeking out new worlds and new civilisations' so they can run into people.
And lots of other sci-fi shows are full of people running away from things.
The obvious show to cross over would be Blake's 7, just for the look of sheer disbelief on Blake or Avon's face when a Federation captain goes, 'the Federation are friendly'. Yes, precisely *that* look. I suspect that Mal Reynolds's look would be similar.
Or possibly Crichton et al wormholing into Star Trek and really liking it but having to go back to their 'verse to stop Scorpius.
( Other Days )