$24.99 per month including unlimited long distance calls within the US and Canada as compared to around 3 times that price for a comparable land line with all the features Vonage includes for free, not even counting long distance charges you'd have to pay. (You can pay $14.99 per month without the long distance thing.) Plus, you can see a log of all incoming & outgoing calls (including caller ID) and access your voice mail online. You can also do cool things like add virtual phone numbers in any area code which ring at your home, so that friends & loved ones in other areas can make local calls to your virtual number(s) and avoid paying long distance. You can bring your VOIP router with you when you travel & hook it up to any broadband connection, and then make and receive calls as if you were at home. Lots of very cool features. Go to vonage.com to read more about it.
As far as 911 goes, as long as you register your address it works just fine. Vonage reminds you to do this so often now that you'd have to be an imbecile to forget. Beyond that, more and more local phone companies are tying it in with their local E911 services. And even if you DO forget to register your address, 911 still works -- it just goes to a regional dispatch center and you have to give your address to them, and they forward you to the local 911 center. Vonage is bending over backwards to get any issues they've had in the past with this resolved.
Oh, and I can't get DirecTV at my home -- trees block my line of sight to the satellites. But to be honest, my cable company has been improving steadily since I moved into the place, and now I have dual tuner high-definition DVR boxes that work just fine. No complaints on cable service now.