Icewind Dale, Heart of Winter and Icewind Dale II. Also really like the US box for Tales of the Sword Coast

I'm sure there are more...

I just noticed how homoerotic the cover is. Thanks for ruining doom for me :(

Your welcome. =)

I've only kept a few game boxes, over the last 25 or so years of gaming. I'd have to say that my top three are:

Heroes Quest Before it had to rename itself Quest for Glory, the original box. With the Famous Adventurer's Correspondence School booklet and such. It probably wasn't truly amazing, but it was the first game I bought (ok, had bought for me) for the PC platform.

Baldur's Gate 2 The collector's cards, the enormous spiral-bound book, everything about the collector's edition box is awesome, and so is the game. And if you disagree, you're wrong.

Fallout 3 New Vegas It's a lunch box. It's really hard to appreciate the retro value of that if you aren't at least a *little* bit old.

System Shock (the 1st one), StarCraft II: Wings of Liberty CE and Civilization V CE.

Wing commander prophecy, there is just so much stuff to read in there

The X-Wing artwork is indeed very good.
Overall I think Lucasarts had some great artists working for them. In the time when their adventure games were among the best things available on PC, they always had top box arts too:
http://www.mobygames.com/game/zak-mckracken-and-the-alien-mindbenders/cover-art/gameCoverId,22123/
http://www.mobygames.com/game/secret-of-monkey-island/cover-art/gameCoverId,43341/
http://www.mobygames.com/game/maniac-mansion/cover-art/gameCoverId,39201/

Also, I remember they had some very creative copy protection wheels, for Monkey Island particularly.

Clearly the Starflight cardboard folder. Almost as thin as a vinyl record release, standard box height. Magnificent design that somehow never gotten broader appeal and vanished rather quickly.

Opening a game box will never give you the feel like unfolding this beauty does.

Some of my faves:

Gabriel Knight 1
Gabriel Knight 2
Shadow of the Comet
Shadow of the Comet alternative

Starcraft 2... lovely packaging. :)

Planescape Torment always stood out to me...made me wonder what pain & frustration lies behind the eyes of that poor tortured soul.

That was my first impression, based on the name of the game & that facial close-up of The Nameless One.

Of the ones I have...
Oblivion: Collector's Edition box -- simply beautiful
Dragon Age: Origins Collector's Edition -- Love metal boxes
Prey Collectors ed -- Same reason, shame game isn't half as good :P

Ultimate D&D Collection - very nice artwork on the box.

Another favorite, Ishar 1:
http://www.mobygames.com/game/ishar-legend-of-the-fortress/cover-art/gameCoverId,1262/

Ultima IX:
http://www.mobygames.com/game/windows/ultima-ix-ascension/cover-art/gameCoverId,1649/

(you opened the flap to reveal more art around the avatar)

Falcon 4.0 had a neat case, where it was made like a Trapper Keeper, inside was teh game along with a HUUUUUUUUUGE flight manual (hence why it was made like a trapper keeper).