I don't know if this counts as a game-- it's more of a digital art project-- but it's one of my all-time faves, and I just remembered it. Check out lecielestbleu.com, home of all kinds of interactive graphical and musical Flash and Shockwave experiences-- most notably, the fantastic, bizarrely compelling Flying Giraffes, which can only speak for themselves. Toss giraffes in the air. Leggy, necky, knock-kneed, clattering giraffes. You'll be fascinated for hours.
A new addition to the site allows you to make your own puppets, too, and I plan to play extensively with it. I think this site was nominated, or won, a Webby several years back for art or design or something, and I couldn't be happier to discover the flying giraffes are still around.