There are many sources of miniatures that are used to represent game characters
2d cardboard tokens - low cost and portable
Plastic miniatures from companies like Wizkids - diverse and durable
Metal miniatures from companies like Reaper - durable with great feel
Customized plastic or metal figures from HeroForge - can even come custom painted
Printed miniatures (3d printed in polymer or molded in resin) from Etsy
3d printing miniatures at home
The Denizen still has much to learn; but with some basic painting and drybrushing you can get very nice game-ready miniatures.