Six-handed no-limit hold'em. Set each opponent's style and skill separately, pick your stakes, and play a free session, a fixed number of hands, or a sit & go. After every call or fold you are told what it was worth. Finish a session and you get rated on how you decided.
Style is how they play: a Rock waits for good cards, a Station calls too much, a Maniac bets everything. Skill is how well they read the board and respect the price they are getting — it is not how many chips they have.