If you have: reset router (IE: by pushing button with a pen), disabled firewalls/opened up all Blizzard recommended ports, re-installed ethernet drivers/windows, re-patched diablo 3, then ensured that your ISP can confirm the wiring into your house is okay and that they are not losing packets from your modem/router, you have 1 last step to try.
Flush your DNS in command prompt, then go here
Follow the steps very carefully. Make sure you change the settings both on your control panel/network settings on Windows/Mac AND with your router.
I was able to play for the first time yesterday in almost 3 weeks with no 3007 errors and my worst ping was 250ms for a brief moment, otherwise it was 80-100ms (like it used to be).
I have no idea why this works (hopefully someone much smarter than me when it comes to networking can offer an explanation) but try it as a last resort.
**Make sure you follow every step in that guide including the test commands**
Good luck to all and I hope this helps some of you =)