Found out every Friends episode is listed on the nbc.com Friends website with a plot summary. (http://www.nbc.com/Friends/), and thus every season finale is listed.
Here they are listed: (* means cliffhanger finale)
S1 finale*: TOW Rachel finds out (that Ross is in love with her) S2 finale: TOW Barry and Mindy's wedding S3 finale*: TO at the beach S4 finale*: TOW Ross' wedding (and Ross says "Rachel" instead of "Emily") S5 finale*: TO in Vegas (where Ross and Rachel get married while drunk) S6 finale: TOW the proposal (Chandler and Monica, that is) S7 finale*: TOW Monica and Chandler's wedding (and Rachel's pregnancy) S8 finale*: TOW Rachel has a baby (and Joey "proposes" to Rachel)
I didn't watch all of them, but obviously they usually save the best episode for last. What's your favorite finale? Since this season's finale is most likely the series finale, thought it would be good to ask this question now.
-Frank