Martin Scorsese does not show up in every one of his movies. And when he does, it's often in an easy-to-miss cameo (a photographer in Hugo and The Age of Innocence, a homeowner being forced out in Gangs of New York). But fans rejoice when he gives himself any sort of extended screen time, like when he played a passenger of Travis Bickle's in Taxi Driver. Scorsese's iconic mile-a-minute mouth is always a welcome addition to one of his projects, but in small doses only; can you imagine how exhausting it would be to follow his thought process for two full hours?