In the interest of brevity for those of us who have short term memory loss, here is the list so far. I took the liberty of adding dates. Interesting the actors, directors and even time periods that seem to come up frequently.
1. Monty Python and the Holy Grail (1975)
2. Pee Wee's Big Adventure (1985)
3. The Hangover (2009)
4. History of the World: Part 1 (1981)
5. Spaceballs (1987)
6. Anchor Man: The Legend of Ron Burgundy (2004)
7. Blazing Saddles (1974)
8. Zoolander (2001)
9. Airplane! (1980)
10. Little Nicky (2000)
11. Johnny Dangerously. (1984)
12. A Fish Called Wanda (1988)
13. Freddy Got Fingered (2001)
14. South Park: Bigger, Longer, and Uncut (2000)
15. It's a Mad, Mad, Mad, Mad World (1963)
16. Harold & Kumar Go To White Castle (2004)
17. The Naked Gun (1988)
18. Moonstruck (1987)
19. Role Models. (2009)
20. The Big Lebowski (1998)
21. UHF (1989)
22. Old School. (2003)
23. Groundhog Day (1993)
24. Ghostbusters (1984)
25. The Jerk (1979)
26. Super Troopers (2001)
27. Used Cars. (1980)
28. The Princess Bride (1987)
29. Happy Gilmore (1996)
30. Shaun of the Dead (2004)
31. Talledaga Nights (2006)
32. Brain Donors (1992)
33. A Christmas Story (1983)
34. Office Space. (1999)
35. It Happened One Night (1934)
36. Animal House (1978)
37. Caddyshack (1980)
38. Young Frankenstein (1974)
39. Tootsie (1982)
40. Almost Heroes (1998)
41. Dirty Work (1998)
42. Monty Python's The Life of Brian (1980)
43. Ferris Bueller's Day Off. (1986)
44. Sixteen Candles (1984)
45. Car Wash (1976)
46. Time Bandits! (1981)
47. Dude Where's My Car? (2000)
48. Clerks (1994)
49. Zombieland (2010)
the last one is mine, and here is the awesome opening sequence:
[YOUTUBE]Lz0HFr3VgNw[/YOUTUBE]