For what it's worth - and maybe this shows my age, my nominations, in no particular order would be:
Allied Marine - several pages back, someone said "industrial grot has never looked so good"; I quite agree, and it made me think about the "other" parts of the railway world.
Dave Rowe's "Bevleys" - I was lucky enough to be at the london show with the bedford and District MRS in about 1982 when this was exhibited. it was a beautiful piece of work and may the pre grouping scene utterly enchanting.
Wallsea by Barry Walls. I never saw this in real life, but it was impressive to an impressionable 11 year old!
Lochside by Ian Futers. never liked diesels and never modelled them, but this was beautifully done and very evocative.
Chiltern green. Again, never done anything in "N", but this showed that it wasn't just a toy train.
Allan Downes' various articles about building with card. It inspired me to build all manner of things and choke the hoover.
There must be others, but that's what springs to mind! Oddly, none of them pointed me towards my life-long interest in the Southern railway and the LCDR part in particular.
Stewart