The gantry crane is "the one".
Rocket launchers beat it out for "cool". But for usefulness, PW or TMCC, the crane is king! (versions vary)
Lots for cheaper though. The bubbling oil derrick, and news stand with dog, were my "simple" favorites. As was an operating luggage station.
The lumber, milk, and culvert pipe operations had the next most use, in that order.
A stand alone whistle house so any " cheap locos" have some sound too would be cool.
A modern digital version is made for many of the old talking stations recordings. That module mounted in a new, or old station, would be very cool have too.
