What hit me today, which I think is pretty amazing, is that Animal Crossing: Wild World has lasted me a generation+. I bought my DS for Animal Crossing and have played it substantially over roughly 6 years now. It's weird that I have the next generation and am still playing AC, trying to complete certain libraries (missing 1 fucking fish, 3 bugs, and a handful of paintings) and that this game is still producing content for me to see and new reactions from villagers. Just today I got the "Legendary Brewster Blend" of coffee which I've never seen myself get before, and even Brewster was surprised by his own creation!
Something that I'm really scared of is the activity log. Prior to now I've never known how much time I've invested in any Animal Crossing game (I didn't play City Folk long enough to consider myself hooked, as it sucked) but now I'm able to see that I spent ~3 hours in AC:WW today. I mean, I'm scared for when AC 3DS comes out and the counter is really starting fresh. In the back of my mind I've always wanted to know my time investment in AC games, but at the same time I felt better NOT knowing.
Also, the AR cards are awesome. I get the feeling that they aren't THAT amazing though, since it seems that the cards represent little more than triggers to open files on the 3DS itself. Getting new cards wouldn't open new experiences, since the games/arenas feel pre-loaded. Is there more depth to the concept than a rather cool tech-demo?