Dragon's Lair [$4.99- iTunes link], the original laser-disc (wikipedia it!), fully cell-animated arcade adventure from the legendary Don Bluth is officially, nostalgically available for the iPhone and iPod touch.
If you weren't there to experience Dragon's Lair's emergence onto the arcade scene in the wayback days of yore, it's hard to explain the impact it made. Suffice it to say, if the iPhone version captures that kind of magic, every 30+ year old will download it on sight, and many younger folks might just fall in love with it as well.
It's not Pac-Man or Street Fighter; it's a very different type of gaming experience, so if you've been waiting for it, let us know how it translates, and if you're trying it for the first time, let us know what you think!