Digital Cable, mainly because it carries VH1 Classic. What a great channel. They play the old videos we all know (Robert Palmer's videos with the dancing zombie chicks, "Sledgehammer", etc), plus extremely obscure and forgotten stuff that looks like it was taped on a $100 budget including the camcorder.
Dual-head video cards. Once you set up two monitors side by side, you'll wonder how you ever got by without 'em. I tried 3, but the law of diminishing returns kicked in.. just too much stuff to look at.
ABS brakes. I never really cared for them until I got a car with ABS (a 1988 Ford, believe it or not..American car companies used to be pretty innovative). I can threshold brake to avoid a skid, but that still doesn't beat mashing the pedal as hard as possible and letting the electronics take over. They really work well, especially on slick roads.
And the biggest by far...
THE INTERNET. Every single job I've had since I started working 7 years ago was directly created by the Internet. Tech support/sysadmin for an ISP, web design, web-based CGI programmer, system/admin for an ISP again, partner in a company that runs a network of advertising websites.