The Apple iPod. I keep telling my PC-loving friends that Apple is penetrating the PC market because they have tiny "gateway drug" types of technology that encourages a user to try using Apple products. Those who don't own MP3 players will more likely try out the iPod. Those who own an iPod will more likely try out the iPhone. Those who try out the iPhone will more likely try out a Mac Mini.
PC users who mock Apple's resilience needs to wake up: They have a product out there that is perfect for you and after the first hit, you'll probably come back for more.