Boy Meets World Season One
Freaks and Geeks
Mary Poppins 40th Anniversary Edition
Master and Commander 2 disc
The O.C. Season One

Star Wars Trilogy
LOTR: ROTK EE

Those where the only really "special" releases in far of being great DVDs and movies I was dying for. There's some other great flicks I picked up like Eternal Sunshine and Garden State that I'll watch a ton, but the DVDs are nothing to write home about.

Star Wars
Seinfeld

This was a year of holy grails for me...

Freaks and Geeks
Ed Wood
Seinfeld
Northern Exposure
Simpsons 4 and 5
Star Wars Trilogy

Star Wars Trilogy Box Set
LOTR Extended Editions
Fox/Fortune Star releases
Alfred Hitchcock Signature series

Edit - Forgot to add Looney Tunes Volume 2 and the Tom and Jerry Spotlight Volume 1

Alfred Hitchcock Signature series
Simpsons Seasons 4 and 5
Arrested Development Season 1
Spiderman 2 Superbit
Star Wars Trilogy
Matrix Collection
John Cassevetes Five Films

Well, not all of my DVD's came out this year, but I started my collection this year, so all my DVD's are my favorite purchases this year,

TNAJason - might wanna edit your list. Gotta be careful when you have a capital D next to a colon ... errr

Criterion Cassavetes Box set
Warner Film Noir box set
Warner Scorcese box set
Warner Hitchcock box set

The box sets beat out the individual titles for me.

Arrested Development has to be my favorite release of the year.

Also...
Garden State
Naploeon Dynamite
Seinfeld
Rise + Fall of ECW
Ultimate Matrix Collection
Kill Bill Vol. 2

I somehow ended up with ~240 purchases this year (ouch). I started the year at 353, and currently I am at 592 using DVD Pro's count. Of those, my 15 favorites are (no real order except Freaks and Geeks is #1 and RotK is #2):

Garden State
The Lord of the Rings: The Return of the King: Collector's DVD Gift Set
Napoleon Dynamite
Harry Potter and the Prisoner of Azkaban
Eternal Sunshine of the Spotless Mind
Star Wars Trilogy
Clerks: 10th Anniversary Edition
Freaks & Geeks: Fans Only Yearbook Edition
Dead Like Me: The Complete First Season
Walt Disney Treasures The Chronological Donald
The Great Escape SE
The Last Samurai
Kill Bill Vol.1
Secondhand Lions
American Splendor

Next 5:
The Good, the Bad & the Ugly SE
The Great Escape SE
Chappelle's Show: Season One: Uncensored!
Alice in Wonderland: Platinum
The Girl Next Door: Unrated

ALF S1
Bad(der) Santa
Bubba Ho-Tep
Dawn of the Dead 04
Firefly
Freaks and Geeks
Iron Giant
Knight Rider S1
Magnum P.I. S1
Millennium S1
Napoleon Dynamite
Red Dwarf S 3/4
ROTK EE
Shaun of the Dead
Top Gun

EDIT: I forgot about Final Countdown

What I enjoyed the most was Arrested Development season 1, since I did not watch it when it initially aired.

In no particular order:
LOTR:ROTK EE
Dawn of the Dead 2004
Dawn of the Dead UE
Starwars Trilogy
Master and Commander
The Good, The Bad And The Ugly: 2-Disc SE
Ginger Snaps II: Unleashed

Monster Legacy Sets
Star Wars
Flight of the Navigator
Good the bad and the ugly
Film Noir from Warner
Hitchcock

Garden State
Queer as Folk Season 1
Spider Man 2
Aladdin Plat. Ed.
Shaun of the Dead

Warner Film Noir box set
Warner Scorcese box set
Loony Tunes Golden Collection vol 2
Hellboy Director's Cut
Batman: The Animated Series vol 1
Keen Eddie
The Lord of the Rings: The Return of the King
Spider-Man 2
The Thing CE
The Shawshank Redemption SE

I didn't buy much, but I'd have to say the Scorsese boxed set was up there. My favorite screener this year was the Freaks & Geeks yearbook, though.

Dawn of the Dead UE

YES! Add Ed Wood:Special Edition Baby!

Garden State & ROTK EE.

All 3 LOTR EE
Star Wars Trilogy
Ultimate Matrix
Pee Wee's Playhouse 1 & 2
Pee Wee's Xmas Special
Sleepaway Camp Box Set
The Tick
Reno 911
KISS Symphony
Space Truckers
Spiderman 1 & 2 Superbit
Starship Troopers Superbit

Ed Wood, all the hoopla of everyone getting this before it hit made me nuts. I had to have it! I tracked down a copy on half.com for full MSRP but hey it wasn't any more money than if I had gotten it at FYE. Anyway, I brought into school and bragged to all my fellow film students. That was fun. Probably the most memorable purchase of the year and also it happened to be my 500th DVD.

Damn you! Isn't that the one with the Cross-Dressing featurette? If so,then damn you,if not,then damn you for getting it sooner!

Abbott and Costello - The Best of Bud Abbott and Lou Costello, Volume 3
The Lower Depths
Stray Dog
Lost in Translation
Schindler's List Gift Set
House of Flying Daggers
Ikiru
Warriors of Heaven and Earth
Nói
Red Dwarf - Series 3 & 4