6, 10, 15mm?

[LawnRanger]

Spot on Bunny 
      Very nice 15mm you have ...what you planning next?

[Steam Flunky]

I have to say 15mm.
I play napoleonics in 10mm as its the mass of regular battalions that makes it look "right".Large battalions or/and large battles. Single figures are less important but you can still do lovely command stands.
For fantasy i like large battles as well but characters like leaders, heroes and wizards are more important than in historical battles so that extra few milimeters makes a lot more detail and character possible.
A few pics of my 15mm fantasy figs.
http://www.flickr.com/photos/torq42/sets/72157628765291567/