Upvote:1
Use the Betamax price comparison table to find the VoIP provider with the cheapest rates for a given destination. Dialnow recommended above is part of the Betamax network as well.
Upvote:4
It depends on where exactly you want to call really; Each VoIP company offers different prices for different countries! You should specify the list of countries that you wanna call and check the cheapest options! For example I use dialnow for calling Iran from Italy (which actually doesn't matter generally for a VoIP call from where you are calling since it is using IP protocol). And I should add that I am really satisfied with that because it costs me less than 2 cents/min for landline and less than 3 cents/min for mobile numbers (for Iran). For rates for other countries check here.
I also checked the Viber VoIP call prices (Viber Out) couple of days ago which seemed pretty good (specially to the landlines). You can check its prices here.