1.) Free online with the playstation network. It seems to work just as well as live and has no subscription fee
2.) A cheap blu ray disc player - If you have an HDTV as I do you will definitely want one of these since hd-dvd is down the drain.
3.) Playstation 3 exclusives - If you like games like metal gear, littlebigplanet or other great playstations exclusives it's great
4.) Great network compatibility - You can just turn windows media player so sharing is on and PS3 will auto-recognise it
5.) The XMB - This is the cross media bar it is so easy to navigate unlike microsoft's broken system
6.) It's now pretty cheap at only 399
7.) A built in hdd - It's 80 gigs now even though mine is only 40 this is a fair amount of space for music video and game storage
8.) Compatibility with PSP - I also have one of these that I acquired recently. You can do remote play or easily transfer data both ways.
9.) Yellowdog - You can install other operating systems such as yellowdog or ubuntu on your ps3 SWEET!
10.) The controller - The slight tweeks from ps2 make it amazingly good