The Back To The Future trilogy is available in open matte on VHS, Laserdisc and DVD.

I have another film with Michael J. Fox called "The Secret of My Success" on Laserdisc and it's open matte.

On Laserdisc, I also have Predator (P&S), The Twilight Zone (I think it's P&S), Frantic with Harrison Ford (P&S).

All of these are French Laserdiscs besides the BTTF trilogy.

Spider-Man 1 & 2 are available in Fullscreen on DVD. Spider-Man is a true open matte presentation since it was filmed on flat 35mm. The second movie was shot on Super35 in 2.39:1 so it's half opened/half cropped exactly like T3.

The Big Lebowski does exist on DVD and it's a true open matte version without any real cropping issues.

BeetleJuice, The Faculty, The Matrix trilogy, Reservoir Dogs... all of these are available on Fullscreen DVDs as well.