Portugal
 

Little information on Portugal here so will add my recent experience. I only need data so dont look for packages that include calls and texts.

Bought a Vodafone Vita Net Plus dongle, couldnt get a SIM only version, took the SIM out and am using it in my device. It costs €10/720Mb, it doesnt do out of country texts & I have not tried it for calls either in or out of country. It hasnt complained about Skype and it allows me to use my VPN service. Its easy to top up, once you've figured which page on the user website to use, using a UK credit card.

Been using this for just over a month now & very happy