It sounds like AussieLegend also thinks we should use proper English in the credits.  I don't see anything about this in the manual of style or in the TV-specific guidelines at WikiProject Television.  This might be a matter that could be taken there to see if there's a consensus on what should be done.  I personally think we should go with what the episode credits say (using things like Jeffrey Lieber and J.J. Abrams & Damon Lindelof).  This way, we preserve the information about who worked together and who worked separately.  Since the information is in a table and not in the middle of a sentence, I see no reason to correct grammar here (and I'm usually really picky about grammar).  The best example that comes to mind is Pirates of the Caribbean: The Curse of the Black Pearl where the credits list writers as Ted Elliott & Terry Rossio and Stuart Beattie and Jay Wolpert.  Clearly, the first two worked together, while the last two worked independently of the others.  I think that information is important and (if it were an episode of a TV series) should be listed as such in the episode table.  Whenever I type in writers, I always go with whatever the episode says (of course, from what I can remember, I've never dealt with an episode from more than two writers before).  Again, though, there is no statement anywhere in policy that I can find that specifies which format should be used.