TNG: Dark Page
I thought Majel Barret did a fabulous job, and really sold the shame and guilt well. I only recall seeing this once before, but, I'll say it again, great performance by Majel, IMHO.
ETA: TNG: Inheritance
I love Fionnula, She always rises to the Quality of the shiow (Or brings it up). Even at 72, she seems to be doing at least 3 or 4 projects a year.
I'd love to see her with one more Star Trek Part (Or any other Iconic Swan Song Role)
Same goes for Ronny Cox now at almost 76, but, he seems to have slowed down to only a single project a year for most of the last 9 years