What is your favorite of ALLLLLL time? Even of today. Leave a link to it when posting.
These things are usually what comes to mind when remembering a game. It really does have an effect on people whether they like to admit it or not.

Mine may be a little obvious because of my avatar, but it's definitely Tom Clancy's Rogue Spear.

http://www.youtube.com/watch?v=A7xiK-snyJk

Fallout

http://www.youtube.com/watch?v=hMmdtxIm0Rk

Oh You say rogue spear i say raven shield

http://www.youtube.com/watch?v=nG-8-hhhEHY

Honestly, any one that I can skip. If they need to introduce me to the game, that should be in the game, otherwise it shouldn't be in there at all.

Those ones that they don't let me skip are just really annoying.

First Fallout had the best intro.

Frankly, I can't think any recent games that had memorable enough intros. Not sure whether this is my favorite, but it surely is still one of my tops.

Command & Conquer: Red Alert

Since my avatar probably says it, Road Rash on the 3DO/PSX/Saturn/PC:
http://www.youtube.com/watch?v=s_F-78OJUB4
That intro is so nostalgic for me and it is just too cool.

Return to Zork

Ultima VII

Best intro for the best game.

Fallout 2 is also up there.

Fallout's intro for really getting you ready for the game and Duke Nukem - Time To Kill's intro because it is awesome http://www.youtube.com/watch?v=X5nJWdHBVhQ - one part is NSFW, I guess. And this Company Of Heroes intro http://www.youtube.com/watch?v=12Z2qk7el8o for it's no bullshit depiction of Omaha Beach. I also really like the intros from most of the Command & Conquer games. :)

Age of empires 1
Empire Earth 1
Age of empires 2

For me, The Witcher - damn that fight with the Succubus looked cool!

Blizzard's games come to mind for me... especially Brood War and Diablo 2.

My favorite is Mechwarrior 2