28mm (1/56) is the market leading scale at present, that said the available figures are all subject to different manufacturer's interpretation of what that scale is!
25mm (1/72) a traditional scale for metal wargames figures and seemingly the scale of choice for Valiant Miniatures for their WW2 offerings.
20mm (1/76) traditionally the scale of choise for WW2 gamers, though an increaseing number if companies are producing this period in 28mm now.
15mm (1/100) a popular scale with relatively few offerings in plastic, again mostly used for WW2 period at present.
