>Us! (EPISODE 11: MIDDLE GROUND)
>The Balcony scene w String and Avon.

That was an interesting scene for a couple reasons:

1) You got some humor (no matter if it was coated in something more dramatic) in a season where their relationship was terribly strained.

2) As I have said before, some storyline (like a prequel) about how Stringer and Avon rose to power, from snatching treats at a candy store to first gaining control of The Towers, would surely be great.

3) When you think about it, Avon had already given Muzone the go-ahead to get Stringer. He knew his man, his friend before they even sold a single ounce, had less than a day to live--and his death was essentially by his command. He even asks Stringer when's he meeting with the contractor (or whoever that white guy was), so he has a time and place for the set-up. That's rough.

The manner in which the Stringer / Avon relationship fell apart and led to murder reminded me strongly of Michael / Fredo in Godfather II.

Also, as you mentioned, the jailhouse confrontation in S2 is when it all most obviously started to fall apart. That's why I included it in the number three spot for that season's list.