Would that be the Magnificent Ferengi, where they have to go and rescue Moogie (or was it Zek?) from the Dominion? That was truly an awesome episode, and ranks somewhere in my top 5 DS9 episodes of all time.
I've recently finished watching season 7 of Castle, as season 8 has just started. Also have queued to watch season 3 of Agents of SHIELD (started yesterday), season 2 of Flash (next tuesday), season 4 of Arrow (next wednesday), season 5 of Once Upon a Time (starts sometime soon), season 6 of Walking Dead (starts next month), Dr Who (great start to the new series).
Good TV shows are like buses. Months of waiting for one, and then 7 come along at once.