...
For me it's Bobby Briggs - he's hilarious in most of his scenes, in the first season with the Major and in many other scenes. His mannerisms are hilarious and over-the-top and when he loses his temper it's an absolute blast. I laughed so hard at his scene with Mr. Pinkle, and especially at his -
"AFRAAAAAIID!?! AFRAAAAAAAIIID?!?!?!?"
- before Laura's funeral.
And he's also a highly likeable character too IMO. He's youthful, full of energy and life, has initiative and good intentions for Shelley...
The only time I didn't like him was in the pilot and the first episode, in which he just seemed like a jerk.
There was a fiish..iinn the percolatrr!

Piper Laurie really is an great actress. 