$18/month? If I got all content that was produced for the entire history of the BBC, and all future content, then yes. I'm tired of having to wait for new episodes of QI to show up on youtube.
But keep in mind that content production is a fixed cost, so if you increase the number of subscribers you can lower the cost per subscriber.
You don't quite get everything-ever. Certain programs (including films) are made available online on iPlayer for a few weeks, but after that you usually have to wait for it to be repeated on TV (and usually again on iPlayer).
I'd be willing to pay a lot more than that. If they wanted to charge me what Brits pay that would be fantastic but considering that is not currently an option I'd settle for paying more too.
It is cheaper if your TV is black and white. You also get a reduced price if you are legally blind, although I am not sure how much of a discount you get.
Overall, I think the TV license is brilliant considering it provides us with an ad-free TV and news network.
Plus, you only actually need a license if you watch TV "as it is aired." I.E. DVDs, recordings etc. don't require a license. It's less of a TV license, more of a live TV license.
It always struck me as odd however that watching streamed live foreign TV on your computer counts under that however, and you need a TV license for that, to help fund the BBC.
If it was the only way my wife and I could get the content we would pay. We would even pay a lesser fee for the ability to stream some of their shows they don't allow to stream outside of Britain.
Radio is free -- you're only paying to watch live broadcast video (or to watch video that's simultaneously being broadcast, so live streaming of a TV channel counts).
Normal cable which is most of the channels does have adverts. "Premium channels" like HBO and Showtime and Starz do not, because they grew out of being uninterrupted movie channels ("Home Box Office").