Chalk, oil-based or water-based? I find that water-based paint tends to wear off on heavily used pieces.
Personally, I use chalk (several brands), metallic paints (I swear by Modern Masters), gilding wax (such as Inka Gold or Rub n' Buff), and furniture wax, both colorless and colored.
Heavily used pieces might benefit from a sealing finish, be it wax or lacquer.
@blujeanne615 I'd say it depends on the piece of furniture you're using it for and where that item will be located (high-moisture zone vs. a regular area in the house). I do love chalk paint for its ease of use though!