Ok, a flipper is when the movie is on 2 sides, not when the widescreen version is on one side, and full frame on the other and the same with the extras.
lotr ee
woodstock dc
The Shining (tv version)
spawn box set
Das Boot Superbit

Sleepers
Woodstock
The Pelican Brief
Lawrence of Arabia LE
Lord of the Rings: EE
The Godfather Part II

the wild bunch
FOTR:EE
Lawrence of Arabia : LE
Sleepers
Godfather Part 2
Das Boot

I think the only ones I have are V: The Original Miniseries and V: The Final Battle.

Rob

Lord of the Rings EE
Stalker
Pearl Harbor Vista Series

Spawn
Das Boot
Pearl Harbor

Movie on 2 discs:

LotR: EE
Stalker

Flipper:

None!... Until Dances with Wolves: SE, at least. I hate flippers.

Das Boot
Ben-Hur
Gettysburg
Lawrence of Arabia
The Godfather Part II
Children of Paradise
The Lord of the Rings: The Fellowship of the Ring EE

LOTR:EE
Godfather Part 2
Pelican Brief

I believe Dr. Zhivago is this way.

I have one flipper, Dawn of the Dead, the Anchor Bay one.

2-disk:
Pearl Harbor Vista Series
LOTR: FOTR
Lawrence of Arabia: LE
Dune DC mini-series (okay, so 3 disks, but...)
I have a Spirited Away version that's split over 2 disks.

Most of the ones mentioned already...

I need to cut back!

Off the top of my head...

Pelican Brief
Pearl Harbor
A Time To Kill

most of the ones mention (I guess it doesn't bother me that much) +
Gone with the Wind
and soon, Dances with Wolves

Flipper to me doesn't mean the longer films that are on two disks. I consider flippers movies like "A WOMAN UNDER THE INFLUENCE" or "GOODFELLA's", average-lengthed movies that you need to flip in the middle for no apparent reason.

LOTR EE

Flipper:
Stargate(I need to get the SE)

Ghoster

What I don't understand about "Goodfellas", is that the Disc is labeled Widescreen on one side, and Full Frame on the other. But when you watch Widescreen, half way through the film, you have to flip it over. I couldn't tell you if you had to do the same with the Full Frame version, because I haven't watched it.

Sleepers
Gone with the wind

Got rid of my one and only flipper when the SE of The Color Purple was released. The only 2-discs I have are Godfather 2 and LOTR:FOTR EE. I assume LOTR:TT EE will be a 2-disc as well so that will bring the grand total up to 3.

A lot of the ones above.

I'm not home, but I think The Stand and It and the TV movie version of the Shining are all flippers, too.

I think The Right Stuff is the only one I own. Ironically, it's the first DVD I ever bought.

2 disc:
An Evening With Kevin Smith
FOTR:EE

flipper:
The Terminator
T2: UE
Austin Powers: International Man of Mystery
The Usual Suspects: SE

Flipper, movie on two sides:

Gone With The Wind
Ben-Hur
Doctor Zhivago (DVD-14, plus DVD-5 for extras)

Flipper, with multiple sides for extras and/or P&S transfer (contents of 2nd side in "()"):

It's A Mad Mad Mad Mad World (extras)
And Now For Something Completely Different (P&S)
Blazing Saddles (P&S)
Superman: The Movie (extras)
UHF (P&S and extras)
MST3K Volume 1 (original pre-riffing movies)
Terminator 2: Ultimate Edition (extras, DVD-18 version)
The Usual Suspects: SE (2 transfers on side one, extras on 2nd)
The Producers: SE (same config as The Usual Suspects: SE)

2-disc sets, 2nd disc for extras:

The Best Arbuckle/Keaton Collection
Walt Disney Treasures: Silly Symphonies
Walt Disney Treasures: Mickey Mouse in B&W
Walt Disney Treasures: Mickey Mouse in Living Color
Walt Disney Treasures: The Complete Goofy
Walt Disney Treasures: Behind The Scenes At Disney Studios
Walt Disney Treasures: Disneyland USA
Snow White and the Seven Dwarfs: Platinum Edition
Citzen Kane
Singin' In The Rain: SE
Lawrence of Arabia: Limited Edition (2nd disc has 2nd half of movie and the extras)
8 1/2: Criterion Collection
A Hard Day's Night: Collector's Edition
Monty Python and the Holy Grail: Special Edition
One Flew Over The Cuckoo's Nest: SE
Close Encounters of the Third Kind: Collector's Edition
Amadeus: Director's Cut
The Abyss: Special Edition
Big Trouble In Little China: Special Edition
Walking With Dinosaurs
Artificial Intelligence: Widescreen
Shrek (extras and two transfers on two discs)
Moulin Rouge: Special Edition
Monsters Inc.
The Fellowship of the Ring: Widescreen
Spider-Man: Widescreen
Minority Report: Widescreen
Forrest Gump: Special Collector's Edition

Multiple Disc Sets:

The Beatles Anthology (5-disc)
The Fellowship of the Ring: Extended Edition (4-disc)
The Fantasia Anthology (Fantasia, Fantasia 2000 and Fantasia Legacy supplements disc)
MST3K Volume 1 (4-disc set)
Classic Monsters Collection (8-disc: Dracula, Frankenstein, The Mummy, The Invisible Man, Bride of Frankenstein, The Wolf Man, Phantom of the Opera, and The Creature From The Black Lagoon)
Charlie Chaplin Boxed Set (4-disc: City Lights, The Gold Rush, Modern Times, and The Great Dictator)
The Beatles Ultimate DVD Collection (4-disc: Help!, The Making of A Hard Day's Night, The Beatles' First U.S. Visit, and Magical Mystery Tour)

Wow... The Right Stuff was the first DVD I ever bought as well! I recently sold it preparing for the SE which will be out June 10.

As far as flippers...

Rosewood
A Time to Kill

And if you count these...
Spawn Seasons 1, 2 & 3
Stephen King's The Stand (DVD-18)

Teenage Mutant Ninja Turtles: the movie
The Transporter
Diva..Ah Hey! (this flipper disc is an odd one. they're both widescreen. only difference is, one side is anamorphic and the other side is not)