Which data SIM to buy that will work all over Europe?

[Lag]

I'm in Europe for 4 weeks (Greece, Germany, Italy, France, and Netherlands), I'm after some advice on which pre paid data SIM I should buy? I'm currently in Greece, I spoke to a lady at an electronics shop who said she could sell me a Cosmote SIM for 35 euros which included 12gb and suposibly works all over Europe. Is this correct, or is there a better option?

I'm going to scandanavia after Europe, will this SIM work there as well?

[svenn]

Just order it put it in your phone and enjoy

https://www.amazon.co.uk/Three-Mobil.../dp/B01M3VJ2B2

[peterdoo]

Originally Posted by svenn

Just order it put it in your phone and enjoy
https://www.amazon.co.uk/Three-Mobil.../dp/B01M3VJ2B2

Please don't give hints which will give headache to the user. Delivery to Greece takes 2 to 8 days. They will probably not stay 8 days in the same place and wait all the time inside that place for the delivery (couriers never tell the exact time and if you are not there, they postpone the delivery to other day, again without telling the exact hour). And how will somebody from Australia top-up a SIM which can only be topped up using an UK credit card? And then the SIM only allows 3G roaming and no tethering. 3G networks are being dismanteled slowly in Europe. They are slow and have each day smaller coverage.

There is a page with excellent explanation of the EU free roaming:
http://prepaid-data-sim-card.wikia.c...European_Union

And for the SIMs that can be bought in Greece. The page explains which ones work in the whole EU:
http://prepaid-data-sim-card.wikia.com/wiki/Greece

[svenn]

But you don't have the 12 GB data.

http://prepaid-data-sim-card.wikia.com/wiki/Greece

Ok the 3g-network is a bit shitty but anyway.