Forever and always a loyal fan of the good ship Enterprise.

It'd be hard to pick my favorite five. But here are some that come to mind, in no particular order:

"The Trouble With Tribbles"

"A Piece of the Action"

"Day of the Dove"

"Patterns of Force"

"The Squire of Gothos"

"I, Mudd"

"Plato's Stepchildren"

Okay, more than five. I really like the original series.