Well 22 years of Sesame Street is a long time, and I have seen probably about half of the episodes that have ever been made, but here's a few of mine starting with the most Recent
Luis Breaks his Arm (1984-1985 Season)
Mumford does a Magic trick that makes Slimey really Big and Oscar is upset (1985-1986 Season)
Leo the Party Monster moves to Sesame Street (1986-1987 Season)
Elmo won't stop saying the Word Cookie and annoys Oscar, Gina Babysits Ernie's Niece Ernestine (1987-1988 Season) Yes there actually was an episode with Ernestine in the street Plot that year, but No Ernie he was just mentioned
Maria almost goes into Labor and Grungetta plays a major role in this episode (1988-1989 Season)
Big Bird and Fluffy do excersizes together (1989-1990) Season
The week long of episodes when Hooper's Store is Rebuilt (1990-1991 Season)
The Montana episodes from the 1991-1992 Season
Telly dresses up a Brick with a Coat and Hat, and annoys Grungetta with it (1992-1993)
Big Bird Launches Slimey into Oscar's Can All the way from the See Saw in the playground) 1993-1994
1994-1997 Is pretty much unknown
1997-1998 Season, The episode when Big Bird wants to change his name, this was not too long before Slimey's Spaceship headed for the moon.
1998-1999 Season, the episode when Big Bird can't stop sining C is for Cookie. Although this was the first episode to show the newer updated, it was great to see Cookie Monster have a semi starring role in this episode for the first time in about 20 years. Also a good way to inclue his classic song as part of the main story.
2000: I didn't really care for this season in general. But if I had to pick a favorite episode I'd have to say, the episode when Oscar's friend Felix visits who is a grouch but likes things neat.