Going For Flow

Almost any discussion about the benefits of game play includes the concept of flow.  And discussions of the flow experience usually include mention of the psychologist who coined the term flow — Mihaly Csikszentmihalyi (pronounced: Chick-zen-meh-hall-yee  I hope).  Flow is that state you enter when you are completely absorbed in what you are doing, and includes a deep sense of pleasure.   In this TED Talks video  Csikszentmihalyi describes what the flow experience is and how he identified it.

Which games or activities cause you to experience flow?