Vonage is the biggest voip provider and the most well known. Their voice quality compares to landlines.
They have plans starting at $14.99 for 500 minutes or $24.99 for unlimited local and long distance calling in the US, Canada and Puerto Rico.
Phone Power offers an unlimited plan for $19.95/mo which includes unlimited calling in the US and Canada. They have a promo price of $9.95 for the first three months.
They offer a residential plan of $200.00 for 2 years for 2 lines.
Lingo offers the best plan for international calling. Their $21.95/mo Chatter Box plan offers unlimited calling in the US and 22 countries.
They offer good call quality and many additional features like voicemail, call forwarding..
Packet 8 offers their unlimited plan for $24.99/mo which includes unliimited calling in the US and to 9 other countries. For $5.00 more a month, you can add 35 more countries.
They also offer an annual plan for $199.00/year.
Voip.com offers an unlimited plan for $19.95/mo which includes unlimited calling in the US, Canada, and Puerto Rico. They have free shipping, free first month, and low international rates.
They also offer an annual plan for $199.00/year.