Flames of War- Resource - Linklist Manufacturers of 15mm Terrain -

Building Manufacturers

4Ground - Range of European 15mm and 28 mm buildings for WW2
Area 9 - Another Range of 15mm and 28 mm buildings for WW2
Baueda Wargames - 15 and 28 mm scenery, an Italian manufacturer with expensive prices outside Europe
Crescent Root Studio - WW2 building manufacturers of variety of scales (15, 20 and 25-28mm)...their site often says they're not accepting orders, but they're very popular
Gamecraft Miniatures - a number of different lines of buildings
Eslo Terrain - variety of scales, buildings and terrain
Essex Miniatures - assorted scenery and buildings
Faller - TT & HO scale model railroad supplier with kits for buildings
Battlefront - Their Battlefield in a Box series of WW2 buildings is quite nice.
Gale Force Nine - in conjunction with Battlefront (Flames of War) various pieces of pre-painted terrain and accessories
Fieldworks - manufacturers of ruined buildings of several scales
Frontline Wargaming Various scales of buildings for WW2 and other eras
Hovels - huge range of buildings and accessories for almost any scale/period
International Models - scenery and accessories
Ironclad Miniatures - Several scales, very nice looking stuff
Kerr & King - very nice stuff for various scales. I have several of their buildings, and quite recommend them
Kreative Scenery- range of 15mm scenery and buildings
Long Range Logistics - several scales and eras, buildings and scenery
Miniatures Building Authority - Buildings for various scales and eras
Miniature World Maker - Nice range of buildings and accessories
Monday Knight Productions - Roads, rivers, and minefields, all in flexible latex
Monolith Designs - Buildings for several scales and periods
Musket Miniatures - I have a few of their buildings and accessories. HIghly recommended range of buildings for various scales and periods
PitYak Studios- NZ manufacturer of range of buildings and scenery
Stonehouse Miniatures - Nice-looking stuff for several period and eras
Timecast- Very nice looking stuff based on historic buildings, comes in a few scales
Total Battle Miniatures - a wide range of buildings for various scales
Warbases- a small range of mdf buildings you put together...sounds durable!

Finished Terrain

Wargame Innovations - a big variety of pre-painted, finished boards that fit together in various ways.
Total System Scenic - More prepainted, modular boards that fit together...these come in 1' and 2' sections.

Paper Buildings
Strategery's Paper Terrain Heaven - after starting this list, I decided to make a whole guide just for paper and cork buildings...there were simply too many choices to add here.