Whats the best online international calling card?

[bolido2000]

What are people using nowadays? I used to use Bigzoo and quality was not great and many times I would get busy tones. They went belly up a couple of years ago.
I want to make calls using my celll phone.

 

[aceO07]

I use www.onesuite.com

 

[mzkhadir]

I use cleanasiacard.com