Depends on the situation. However, my wardrobe consists of:
Five pair pants (all long, silk, linen, etc.)
Six shirts
Four skirts (working on number five)
Three vests (working on number four and five)
Some assorted bodices for fairegoing - five or six. I'm working on a set of stays.
One justacorps
Two belts
Three Howard Pyle-inspired sashes
One pair boots
One pair shoes (looking to replace the buckles)
One pair knit socks
Two tricorns
Four or five waist cinchers (when the really Hollywood look is required)
I'm sure there's more but I can't recall right now.