Ian Rice's North Cornwall Mineral, a very beleivable freelanced railway company, uncommon in this country outside of narrow gauge models. I think his writing helped as much as the actual layout with the inspiration, he managed to weave the trials and tribulations of building and running the model locos into a story about the trials and tribulations of running the (imaginary) real thing.
Flemming Örneholm's Eaglecreek & Northern (Model Railroader October 2006), Very good modelling, but it was the concept that I love. I like the US idea of a layout that actually goes from-to somewhere (as Buckingham and Jas Milham's layout do) but this fits into a reasonable UK sized room. The seperate diorama concept works very well to allow different sections of scenery without any unrealistic transitions.
Chiltern Green and Luton Hoo, I think partly because it was somewhere I knew. Whilst walking along the trackbed fo the Hatfield Luton and Dunstable we came across a ditch across the track that we decided must have been a baseboard joint!
I find it interesting that for some people, the inspiring layouts have to be in their sphere of modelling interest. Not a critism, just an observation. To me great layouts transcend subject.