Take a look at Continental card at http://phonecards.russianatlanta.net/p/info.php/Continental

Continental cards have no service fees, low per-minute rates, and many local and toll-free numbers for calling from Europe. I personally use this card for many years and it's been working great. 

You can find cards with lower per-minute rates, but overall I like Continental the most for overall value and ease of use.  This is a virtual card -- the PIN is emailed to you within few minutes after purchase.

Bon Voyage!