Thought I'd get this one started. Here's a list of what I have and can do World War II:-
28mm. Rules of Engagement( British Airborne, Germans, Russians, American Infantry, Airborne) Skirmish
20mm. Blitkreig Commander( Romanians, Russians, Germans, Americans). Battalion, Brigade,Regimental
Rapid Fire
Napoleonic:-
15mm. Napoleon's Battles( Russian Army)
Napoleonic Naval:-
1/2400. Trafalgar( Warhammer Historical) ( French, Spanish and British Fleets)
Form Line of Battle ( Ship to ship and Squadron/fleet actions)
American Civil War:-
15mm. Fire and Fury (Large Union and Confederate armies)
Ancients:-
28mm Warhammer Ancient Battles( Romans)
15mm Field of Glory( Romans, Greeks/Macedonians)
Warhammer :-
28mm Fantasy ( High Elves, Dwarves)
28mm 40K ( Ultramarines, Black Templars, Eldar, Dark Eldar, Tau, Tyranids, Chaos Marines, Imperial Guard,Necrons)
Epic ( Ultramarines, Eldar)
Battlefleet Gothic ( Imperial, Chaos, Eldar and Necron Fleets)
Lord Of The Rings 28mm ( Rohan, Minas Tirith, Gondor, Dwarves, Orcs, Goblins, )
That's it so far. I'll add as I remember or come across more stuff
Cheers
gwaG