Vonage
Phones often don't work, false advertising, rip-off fees to cancel service
Vonage would be great if it actually worked. I had Vonage for a year, but more than half the time, it did not work. The quality of the sound is so bad that I often had to call people back with my mobile or Skype account. Also, whenever there is a problem, which happens very often (phone, fax, ...