Some other interesting things about my collection according to Guzzlefish:

I actually have 4 movies with Judge Reinhold (and, no, it's not Vice Versa).

I actually have 3 Jason Lee movies, none of which are made by Kevin Smith.

Although Ben Affleck seems to be a favorite in this thread, I only have 2 of his movies (Pearl Harbor, Sum of All Fears).

I only have 2 Harrison Ford movies (Patriot Games, Clear & Present Danger), 2 Denzel Washington movies (Glory, Remember the Titans) 2 Al Pacino movies (Glengarry Glen Ross, The Insider) and 2 Ed Norton movies (Fight Club, Red Dragon).

Only have 1 John Travolta movie (Pulp Fiction), 1 Jack Nicholson movie (A Few Good Men), 1 Nicholas Cage movie (Adaptation), and 1 Sandra Bullock movie (Speed).

My Guzzlefish gives me:
Monty Python cast - 21
DeNiro - 17
Buscemi & Duvall - 12

Females:
Bardot & Julianne Moore - 9
Stephane Audran - 8

According to Guzzlefish (slightly skewed since I have a ton of wrestling DVD's)

The Rock: 16
Steve Austin: 12
Triple H: 11
Adam Sandler: 10
Bruce Willis: 10
Ben Affleck: 8

Johnny Depp

Catherine Deneuve

According to Guzzlefish, here are the stats...

Al Pacino - 14
Tom Cruise - 13
Brad Pitt - 12

and...

Beverly D'Angelo - 6 (frickin' Vacation movies...)
Susan Sarandon - 6
Janeane Garofalo - 5

Yikes!

Ben Affleck-5
Matt Damon-4
Samuel L. Jackson-4
William Powell-3
Judi Dench-3
Steve Buscemi-3
Bruce Willis-3

Arnold Schwarzenegger

Mel Gibson - 9
Cary Grant - 9

Bill Murray - 8
Keanu Reaves - 8

Minnie Driver - 7
Dan Aykroyd 7
Pierce Brosnan 7
John Cusack 7
Danny DeVito 7
Tom Hanks 7

Seth Green is the top in my collection. Not that I purposely pick movies with him in it, but:
Buffy The Vampire Slayer Seasons 1-4
Angel Season One
Austin Powers 1-3
America's Sweathearts (My wife's, I swear!)
Giving him a total of 9.
Funny thing is, all 9 of his DVDs show up before you reach the letter C in my alphabetical listing.

Matt Damon - 8
Frank Welker (voice actor) - 8
Sarah Michelle Gellar - 7 (Again Buffy 1-4 + Angel give her a big lead)

Another amusing thing is finding the 'extras':
Phil Hawn - 6 (this guy has been in a ton of movies):
Fight Club - Banquet Guest (uncredited)
American Pie 2 - Unrated - College Professor (uncredited)
Heartbreakers -Bank Customer (uncredited)
Cruel Intentions - Subway Pedestrian (uncredited)
The Green Mile - Police Photographer
Austin Powers: The Spy Who Shagged Me - M.O.D. Crime Scene Investigator