I absolutely love the Errol Flynn version of Robin Hood. Granted, it contains some historical inaccuracies (such as the Normans killing all of the Saxons while King Richard was away), but it is still a great movie!
I love all scenes with Will Scarlet (they properly portray him as Robin's squire in this film). Will is a riot, and, I must admit, he's far from a typical squire. Rather than addressing Robin with the proper "milords" of their day, Will is dashingly free in his speech.
Here's an example of his sarcasm:
Will Scarlett: Robin, I've just got word of...
[sees Friar Tuck and breaks off]
Robin Hood: It's all right, he's one of us.
Will Scarlett: One of us? He looks like three of us!
The scene below? He's just informed Robin "it's your skull, not mine" in regard to taking on Little John with the quarter staff.
Maid Marian is a fun character too. She is very properly portrayed as a noblewoman who has led a very sheltered life and knows little of what is actually happening to the serfs under Prince John's merciless rule. Like Will, she says what she thinks.
Then, of course, there is Sir Guy - the evil villain and Prince John's loyal henchman. He's got temper, is merciless to the core, and possesses a very false love for Maid Marian.
Prince John, of course, is the villain. He's quite the sarcastic, pitiless type. Quick witted and sickeningly smooth, his comments always provoke Robin's equally quick and daring sarcasm.
Favorite scenes? Well, I think the final combat between Robin and Sir Guy would have to be everyone's favorite.
Robin Hood: I'll organize revolt, exact a death for a death, and I'll never rest until every Saxon in this shire can stand up free men and strike a blow for Richard and England!