I've been back on netflix for about a year now (previously had it in college 8 years ago*, but it was damaging my productivity, so I cancelled). I started off with the 3 discs at once deal, but I was unemployed and turned into a power user, so they throttled me down. I used to have a 2-3 day turnaround, but it was getting to 4-5 days - quite ridiculous. In recent months, I've been mainly streaming from them, so I changed back to a 1 disc at a time plan. I essentially don't watch cable any more. I can stream almost anything I want.
My only complaints are scratched discs (seriously, people who rub gravel on their discs and talk in theaters should be raped by grizzly bears), the aforementioned throttling, and lack of series I want to watch (currently: House) on instant view.
I also dislike the privacy policy over at Netflix, as you can't clear your viewing history. I'm not complaining because I want to watch a bunch of NC-17 crap. I just want to have the freedom to keep track of my viewing history as I see fit, and to be able to have a little privacy if my wife and I watch something not so appropriate for our parents or kids.
That said, I've really scored on seeing entire series I missed on first runs:
Buffy
Angel
X-Files (most of it)
SG-1
SG-A
SG-U
Terminator: SCC
Deadwood S2, S3
John Adams
Northern Exposure
House
You know, unemployment / college is actually good for something. lol
*Wow, the notion of having had an internet service almost a decade ago suddenly makes me feel really old.