well, features that I know of: the wii has channels, like weather and news. It also has an online store where you can buy games from SNES, n64, NES, sega megadrive, sega master system, etc. but you need to connect your wii to the internet in order to do this. If you have the wii connected to the internet there is also wiiconnect24 which updates your wii when it is in standby. Also, you can connect to other wii's and send them messages (like a message board). There is also a photo chanel where you can upload your photos and make a gallery. you can also make 'miis' which is like an avatar of you, and which you can play as in games. You can also play online with others but you need their friendcode, but there's not many games that support online play.
As for games: wii sports (inc. with the console) is an amazing game. seriously, the it's magical the first time you pick it up and using the new control scheme for the first time. Also, there are 'some' very good games, like mario galaxy, zelda twilight princess, and metriod prime (although I have played MP3 yet). Plus, there are other games worth your time to like super paper mario, re4, mario strikers charged, ssx blur, etc.