TOS era.
Back when redshirts wore red shirts.
Back when you didn't negotiate with bad guys, you Kirk-chopped 'em.
Back when drinking tea on the bridge would get you beaten up.
Back when Klingons could wear turtleneck sweaters and *still* be tough.
Back when the Romulans still painted birds on the bottom of their ships. (Very cool in a flames-on-the-gas-tank way...)
Back when crew-women wore miniskirts. (even in zero gravity?)
And, most importantly-
Back when there was still a real sense of hope and idealism.