I think the DS is their first kick-ass decision. N64 cartridge-format was a horrible one. Game-cube's kiddy flavored attitude is another. Not to mention their disk capacity, but making a game 2-disks isn't that big of a deal. But their worst decision ever was to not keep the alliance with Sony in the glory days of SNES :D But that's a topic for a different thread. I don't mess with my DS much so it's hard to appreciate it to its fullest. But Nintendo isn't exactly known for making the best decisions in any case