In the Season 4 episode, Message In A Bottle, Voyager finally finds a way to send a message to the Alpha Quadrant but they only have a short window of time in which to do it. After some technical difficulty, they send The Doctor through the data stream and hope he can let Starfleet know their whereabouts. He arrives on the ship but everyone's freaking dead and the Romulans have control. I love this one. Here's why:
#1- You know how much I love Romulans. The fact that they managed to get Romulans into Voyager not once, but twice, is amazing.
#2- when The Doctor activates the EMH he finds that he's been replaced--by Andy Dick who is PERFECT in this episode. From a quippy bit about the Dominion War to the EMH Mark II's desire to get (ahem) upgraded, this guest star role was perfectly cast. Robert Picardo and Andy Dick work wonderfully together and their scenes (full of haughty, snippy, one-liners) are hilarious.
#3- This is a romp. Starting out, Voyager was sorely lacking in the romp department but as the seasons progressed, they seemed to get more comfortable with it. And, just as Quark was the resident romp coordinator on DS9, so The Doctor is the head of hijinks aboard Voyager. Message in a Bottle is a perfect example of a Doctor-led, Voyager romp.
I actually finished Season 4 last night so hopefully my Essentials will be up soon! Is there a Season 4 episode I didn't mention that you'd like to read about? Let me know!