I think my greatest moment in TOS just happened -- all 3 seasons in bluray on deepdiscount for about eighty bucks! That's tons cheaper than buying it USED on Amazon.
Actually, my faves are SpockMcCoy in jail in BREAD&CIRCUSES, Kirk in both OTT and subtle moments (risk is our business and 'go to your quarters or I'll pick you up and carry there") and pretty much all of THE EMPATH. Then there's the aformentioned BoT finale and 'gentlemen, I suggest you beam me aboard' from DOOMSDAY.
Geez, I could go on forever!