Truly, one of the best episodes in Friends! My second favorite actually, just next to TOW Everybody Finds Out.
So, what makes this episode so great? Character usage here was balanced, everybody did their part; their best. Also, we see a different side of the FRIENDS, which makes us love their characters more! We see Ross in a euphoric state, Joey and Chandler acting like little kids, Rachel in her I'm-in-the-mood-but-not-later-but-will-be-again-in-a-little-while, Monica in her lovesick state, and Phoebe, well, in being more Phoebe!
And of course, this episode happened in REAL TIME! I really think that writing this episode was difficult, since it was like a stand-up-comedy, where a comic should make his audience laugh and laugh!