I notice that the behavior from Yoda I think of most is when he's first giving Luke grief, before he's revealed that Luke has badly underestimated the little gnome who is really a Jedi master. Yoda's taunting of the heroes, crazy laughing, fighting with R2, tearing trhough Luke's belongings and eating his rations -- that guy is the best IMO, his "mmm? eh heh heh heh!" laugh is great, it conveys an almost nastiness that's masking wisdom.
The sage Yoda is good too, but it's almost a little too straightforward by comparison, very much a teacher that does more teaching through words than experience and behavior. It's all good here too, but the character becomes less interesting as the lessons take center stage.
(this thread discounts the Yoda of the prequels, that of a hard-headed Jedi Council Member and later a Columbian killer attack frog.)