I don't know who thinks they can offer sites like this for free, but it's been my experience that they don't last long, so head over to Video Game Ads while you can.
The site has collected almost 3000 video game commercials from around the world, all freely viewable as long as your browser can deal with it. I had to install Windows Media Player to help Safari along, which, although it caused me great personal pain, was worth it.
You'd expect to see a lot of classic spots (like the first US NES commercial - Will you be the first to play HOGAN'S ALLEY?) and a surprising number of brand new spots, like the Nintendogs ads I just saw on Cartoon Network tonight. And of course the verifiable classics are there... to wit the N64 Smash Bros ads with the costumed mascot fighting.
Some other favorites of mine:
- a Katamari Damacy ad from Japan
- the clueless safari guide spot for Pokemon Snap
- the awesome Animal Crossing series that parodied MTV's Real World
- the incredible "School's Out" GBA ad that was one of Nintendo's early Who Are You? efforts
- Parappa and Ape Escape (and others) in a Japanese Happy Meal ad
- the very hip US WarioWare Twisted spot and the hilarious original Japanese Made in Wario commercials
- the one for Mario Party 6 with Bowser as the prank victim
- and this generic PlayStation one that absolutely gave me chills when I saw it - only once - at a broadcasting convention of all places
Only one spot comes to mind that they don't yet have... the Pokemon Ruby/Sapphire spots that showed real people that physically resembled their animated pokemon.