Also not a list maker here.
1) Glaring lack of focus/attention span.
2) Favorites are constantly moving up and down, so keeping things updated would -- well, see #1.
3) Many of my favorites are admittedly not great, sometimes not even good, films when measured by the movie rating yardstick. (My favorites might only need a ruler.) It gets tiring being dragged because a movie I like isn't on the AFI list or otherwise conventionally considered high-ranking.
The thing about Sunset Boulevard -- it's a fantastic movie, and I love so much about it. But in eighth grade English class (creative writing unit) there was a spate of submissions written by dead narrators doing the basic flashback story with a twist. The teacher stood at the front of the class, papers in hand, very annoyed, and semi-yelled "How are all these dead people telling stories? They're DEAD!" This echoes in my head while watching SB even though I know the answer is to get over it; everybody does it (especially in 8th grade creative writing class); and, it's Billy Effing Wilder so shut up and enjoy.
Sabrina is my sentimental favorite (that I know everybody hates) of the Wilder stable despite its many flaws, particularly that clunky post-somersault line by Holden "You do love her!" or whatever. I usually make a point of being out of the room at that time. From time to time I still try to imagine Lauren Bacall in that role (shudder). You gentlemen may fight over Ms. Hepburn, I will take the dress.
(Throwing the grenade and running out of the room.) I think The Apartment is overrated.