What about the dog barking sound bite?!?!?! I've only had it on one of my steam files and did a double take when I heard it. It could have been the engineer "barking" at the fireman but I don't think so. How bout some female engineers in modern diesels?
Wyhog has some great suggestions, plus I'm sure they talked about other things other than the job at hand like "What's for dinner?" or company/union policies, or "I remember when...". Crew talk could definitely be more realistic, but then someone would complain about some of the language if it got too spot-on.
