The best VoIP service I've come across is definitely from Global Call Forwarding. I purchased my business toll free number from this company and it has worked out so well for us. Very affordable, high-quality number, great additional features, excellent for my biz.
I have purchased a US toll free number and a Nederlands virtual number from Global Call Forwarding and they have been fantastic! I highly approve of the service, very happy with the features, and they offer excellent customer service. This is the best VoIP service for the Netherlands that I Have found. Very affordable rates, too.