If the opposite of pre-programmed automated announcements is a person who is very responsive to the circumstances then one of my favourites was a VXC conductor called Mike with a Somerset accent (haven't seen him for a while but hope he's still there!).
On a long journey with a very early morning start he would begin talking very slowly, with long gaps and use surreal phrases. One morning when the onboard reservations weren't working he drawled "well . . . . you might have noticed . . . there's no seat reservation . . . infomation on this . . . train. It seems the . . . uh, that we can't speak to the uh, . . . . the big computer in the sky. . . . which knows everything . . . maybe it will talk to us later. . . .I don't know what we'll do if it does. If you're in a seat then it becomes reserved . . . . . " (I think he just decided to leave it off all the way). His station announcements were also sleepily slow in the early morning, then after an hour or so, his pace picked up a bit. By midday he was rattling thru all the info. Suits my profile of the day, anyway.
There was another. also on VXC I think, a Yorkshire woman who apparently hates Leeds! She'd mention it in the list of stops, only after a long pause to take in breath, and usually with some disparaging comment. I'm sure she once announced that she couldn't imagine that anyone would actually want to know we'd be stopping at Leeds as if no one would want to go there. Then she corrected herself saying : unless its simply to get off to have a cigarette, - but as Leeds is a non-smoking station, you can't even do that. That's Leeds! she'd grunt.
I'm sure I remember her recommending Huddersfield as being better!
Oh yes, and the sarcastically drole apologies (using the standard apologetic phrases for being late) for arriving EARLY (thanks to the massive headroom in schedules at the end of a run). "We apologise for any inconvenience that this must cause."