HBO's comedy series "Entourage" reflects reality in the case of Adam Sandler. Several Hollywood actors operate on a clique system, and few of these entourages are more productive and prominent than Sandler's gang. Longtime Sandler pals Frank Coraci, Tim Herlihy and Allen Covert usually show up in cameos in Sandler's films, and Sandler's former "Saturday Night Live" castmates Rob Schneider and David Spade owe their film careers to the comic stud. Sandler draws from a repertory of favorite actors who show up in his films time and again, including John Turturro, Drew Barrymore and Luis Guzmán. Under the production umbrella of Happy Madison Productions — the name is a mash-up of the Sandler classics "Happy Gilmore" and "Billy Madison" — Sandler produces films for himself and his friends. Here's a rundown of the Sandlerites. Frank Coraci — After attending NYU with Sandler, Coraci stuck with the comic to direct "The Wedding Singer," "The Waterboy" and "Click." Allen Covert — Another of Sandler's NYU pals, Covert has acted in nearly every Sandler film — although he doesn't show up in "Click" — Sandler produced Covert's starring debut, "Grandma's Boy" earlier this year. Tim Herlihy — Sandler's college roommate, Herlihy often pens Sandler's scripts. His credits include "Big Daddy," "Little Nicky," "Mr. Deeds" and "The Wedding Singer," which he helped adapt into a Broadway musical. Blake Clark — Sandler likes to call on Clark to play crotchety old men in his films. He's joined Sandler in, among others, "The Waterboy," "Eight Crazy Nights" and "50 First Dates." David Spade — Sandler produced the Spade vehicles "Joe Dirt," "Dickie Roberts: Former Child Star" and "Benchwarmers." Rob Schneider — Sandler has also helped out Schneider quite a bit, producing both "Deuce Bigalow" flicks, "The Animal" and "The Hot Chick." Luis Guzmán — Acted with Sandler in "Punch-Drunk Love" and "Anger Management." Steve Buscemi — Buscemi first starred with Sandler in "Airheads," then worked with him again on "Billy Madison," "The Wedding Singer," "Big Daddy" and "Mr. Deeds." John Turturro — Teamed with Sandler in "Mr. Deeds" and "Anger Management." Jon Lovitz — Another "SNL" pal, Lovitz was a supporting actor in "The Wedding Singer," "Little Nicky" and "Eight Crazy Nights." Drew Barrymore — She played Sandler's love interest in "The Wedding Singer" and "50 First Dates."