Veni Vidi Vici - Suppliers of shield pattern transfers. They are always open to suggestions for new lines.
Too Fat Lardies - wargames rules writers of some renown.
Hirst Arts - Supplier of moulds for making buildings, looks pretty good for 25mm figures.
All Terrain - a terrain supplier, very pretty stuff.
Total System Scenic - another terrain supplier.
Terrain Warehouse - suppliers of terrain oddly enough.
SnM Stuff - supplier of paints and other accessories.
Hotz Artworks - game mats, cards ships and other useful accessories.
Principles of War - rules and accessories.
Tiny Tin Troops - Publications for wargamers and accessories.
Nyr Old Design - Figure Painting Service.
Little Big Men - Very good shield transfers and a painting service.
Baueda Wargames - Accessory supplier; tents, etc.
Keep Wargaming - Wargames suppliers.
Hovels - Supplier of buildings, etc.
S & A Scenics - Large scenery supplier.
War Zone - Producers of terrain and other wargaming products.
The Scene - terrain supplier.
Dream Holme - another terrain supplier.
Miniature Worldmaker - superb rubber wargames terrain, very portable.
Precision Wargames Supplies - steel bases, measuring sticks, etc.
Warhammer Historicals - Home of WAB.
The Terrain Guy - terrain supplier, obviously, but also sells well respected gaming mats.
Angel Barracks - accessories & 6mm figs.
The League of Augsburg - late C17th rules.
Timecast - buildings and other stuff.
Battle Flag - flags for wargames armies.
Flags of War - more flags.
Solway Crafts and Miniatures - cloth flags!