Many of mine are listed but here's my list which trys to include several different genre's-
Goodfella's- Best gangster movie of all time with brilliant dialogue (" how am I funny") and great acting from Pacino, Pesce, Liotta.
The Graduate- Hoffman's performance is remarkable and there are so many classic lines.
Annie Hall- Brilliant Woody Allen comedy. Scene where he has dinner with Diane Keaton's family is comic genius.
Fargo- Coen brothers at their best and one of my alltime favorite performances by Fances McDormand.
Full Metal Jacket- Best war movie ever. Classic scenes and performances.
Honorable Mentions- Godfather 1 & 2, Animal House, Dog Day Afternoon, and Pulp Fiction.
Comedies- The In-Laws, There's something about Mary, Meet the Parents, Lost In America, South Park, Love and Death, Spinal Tap, Best in Show and Wedding Crashers.