I'm a big fan of Ronny Cox, & the Jellico B plot in 'Chain of Command' too. Still relish that A plot a bit more though. Warner & Stewart are just too outstanding
Let's see, Data's exploration of Poetry, in 'Schisms' is a rather enjoyable addition to what was otherwise a dark & creepy kind of episode
In The Next Phase, you can consider Geordi & Ro's dilemma the A plot, which made everyone else's reactions & the planning of the funeral the B plot, which was a more interesting aspect
Data's first command in 'Redemption' stands out, amongst what was otherwise a whole lot more of TNG's usual Klingon development
Oh, and the Picard Doppelganger B plot in 'Allegiance' was a lot of fun
And finally, this is maybe the only situation I can say this, as I'm a huge Data fan, but as much as I like Data's featured 'A' plot in Thine Own Self, I did also really enjoy Troi's B plot, about becoming a bridge commander, perhaps more, because it's one of the best things they ever did for her character. That being the case, it somewhat out shined Data's little amnestic jaunt through the dark ages