Ima go ahead and say that this is officially the first episode that truly feels like a Friends episode to me. All the character dynamics are in place, people are talking and acting the way that they will for seasons to come, and the situation has the right balance of pathos and comedy that the show's better episodes have.
The premise is a simple one: Ross and Monica's grandmother has died... or not? ("She may have died. We're looking into it.") Not only does this mean that we get more screen time from the world's best sitcom parents, but we also get to see Ross and Monica's sibling dynamic explored more deeply. This will be mined for its emotional, hilarious depths in subsequent seasons, but we're just getting a peek of the madness to come.
We see that Nana/Judy's relationship parallels Judy/Monica's relationship in a way that can be acknowledged but, ultimately, not overcome. Ross connects to his dead grandmother through her sugar packet collection and then, after falling into an open grave (natch), gets high on pain pills. He becomes very... open. With everyone around him.
The B-plot on this episode is as strong as the A-story: Chandler's co-worker (sporting the world's most gigantic, awesome polka dot shirt dress) mistakenly thinks he is gay, leading to him discovering that he has a 'quality.' What's funny about this is not that he's possibly gay, at least to me. It's that universal feeling that you have been misunderstood and then getting really defensive about it. What takes it to the next level is that by the end of the episode, he's able to own that misperception, and results in him declaring: "I could get a Brian!"
Things are holding steady in the hook-up round-up, with Monica retaining her lead over Phoebe.
The Great Hook-Up Round-Up:
"When my time comes, I want to be buried at sea - it look like fun... Everyone thinks I'm so predictable. After I'm gone, they'll say, 'Buried at sea - huh.'" - Jack Geller on his death
"Well, don't we look nice all dressed up?... It's stuff like that, isn't it?" - Chandler on his 'quality'
"Not the first two, but the second two - Whoa!" - Ross on his happy pills
"That is a wonder." - Monica on her mother's alleged positivity
Episode 1.9: "The One Where Underdog Gets Away"
This is fundamental, transitional moment for the friends. While they have been acting as a stand-in family for each other throughout the year, this is the first moment when they realize that they are more than a substitute family unit. They really have formed loyal, family dynamics that are as constant and complex as any blood relationship can be.
Everyone wants to get home to their families for Thanksgiving. No one gets home to their families for Thanksgiving. And by the end of the episode, no one will care about getting home to their families for Thanksgiving again in any season, because when they gather round Monica's overladen table, they are truly home. *awww*
This episode is a highlight of the first season, setting up gags that will pay off for years to come (including the first iteration of Chandler's ever evolving Thanksgiving-from-hell yarn). It's also the first of many fantastic Thanksgiving episodes to come. AND it's the first episode with the new, much improved Carol, on the scene to remind us that Ross is going to have a baby. Thank heavens for that plot, because otherwise, we wouldn't have gotten to seen Susan's fantabulously epic mom jeans and heard her refer to Ross as "Bobo the Sperm Guy."
Again, no hook-ups. All's quiet on the sexy front for now...
The Great Hook-Up Round-Up:
"You have to take a class. Otherwise, they don't let you do it." - Susan on being a lesbian
"Hey, hey, I'm your daddy/ I'm the one without any breasts." - Ross' take on the Monkees' theme
"Ugly Naked Guy has an Ugly Naked Gal!" - Phoebe
"I guess what I'm trying to say is that I'm thankful that all your thanksgivings sucked." - Chandler
The AV Club seems to have quite a different take on Friends than I do at this point... we'll see if that continues the longer the rewatch rolls on.