Re: Netflix vs. Slingbox
These are complementary services, in my opinion. You may want both. Netflix is great, if they have what you want to watch in their streaming library. Slingbox is great for watching live or local events only available at your house, e.g. a local sporting event.
I also use Slingbox for remote control of the TiVo when I don't plan far enough ahead to use TiVo.com to schedule recordings.
One of the key infrastructure requirements for a good Slingbox connection is the *UPLOAD* speed of the internet connection at your house.