One of my favorite episodes, easily, an essential episode for the series and the character of The Doctor, and thus essential in general, only lacking in hard relevance to the franchise, an opportunity that might be considered wasted considering how much was going on for it already.
(In that regard, consider that Andy Dick appears as the new version of the emergency medical hologram, and there's no reference to Lewis Zimmerman, also played by Robert Picardo, or even Julian Bashir, who flunked his chance to become that model a year earlier.)
But Andy Dick, a pop culture oddity who made his best mark on NewsRadio, is such an unusual Star Trek presence that even without a series of priceless interactions with Picardo (who probably only ever had comparable fun on the show in "Heroes and Demons") his appearance would have helped this episode stand out.
The Doctor's unexpected visit to the Alpha Quadrant has the benefit of another appearance from the Romulans on the show (it was a missed opportunity for the creators to forget about this recurring theme in the later seasons), even though this one's far more random than "Eye of the Needle."
But the biggest development and most relevant element for later episodes and thus for the series as a whole is the debut of the Hirogens, who quickly became a defining alien species both for the season and the show as a whole.
In short, there's very little about this episode that should prevent you from watching it.
Franchise * Series * Essential * Character
Memory Alpha summary.