G: "It's vile."
Q: "I know. It's so bubbly and cloying and happy."
G: "Just like the Federation."
Q: "But you know what's really frightening? If you drink enough of it, you start to like it."
G: "It's insidious."
Q: "Just like the Federation."
This wonderful scene almost got cut for time.
Actually, I always understood that scene was shot as filler, and they did it in several ways, mostly with a comedy twist to it. Then, they did the scene more dramatic as shown, and everyone loved it.
I looked it up, and we're both right appereantly.
The scene between Garak and Quark in which they discuss root beer was added late in production because the episode was coming up a minute or two short. Armin Shimerman and Andrew Robinson wanted to play the scene with an obvious layer of subtext, but director James L. Conway felt it should be played exclusively for laughs. In the end, Ira Steven Behr came down on the subtext side of the debate, saying of the scene "it was never meant as a joke. It was two aliens giving their individual viewpoints about what it was like to live under the Federation. They have serious problems with the whole Federation philosophy, and the fact that it's such a behemoth organization. But at the same time... even though they question the giant, they want the giant on their side when they're in trouble." (Star Trek: Deep Space Nine Companion, p. 261)
According to Ronald D. Moore, when the show was finished it was actually too long, and there was some discussion about whether to cut the root beer scene. Moore fought for it to remain, as it was his favorite scene in the episode. It was almost cut again when the episode was cut into two parts for syndication. He noted, "A great scene. Andy and Armin played it so well, and it's one of the stand-out moments of the season, if not the series. That's always what DS9 is good at, these characters." (Captains' Logs: The Unauthorized Complete Trek Voyages, p. 105)
As for (one of) my favorite Garak scene; when Dukat arrives at the station in By Purgatory's Shadow and nearly strangles Garak because Garak is talking to Ziyal, Garak still has the nerve to say goodbye to Ziyal, saying to Dukat he does have a lovely daughter and that she must take after her mother.