Best amp for GMA Europas?

Depends on what size room they will be in, but I have a Cayin TA-30, 35watts/channel, EL34 amp driving mine. Great combo unless you need deafening volumes in a large room. I rarely turn the volume past 10 o'clock.
You can also email or call Roy Johnson, he will be more than happy to help you out. Check out www.greenmountainaudio.com.
John

I recall a thread not long ago discussing what amps people are driving their Europas with. You may want to try a search.

I used a Kr Audio Antares v300 with the Europas. It only has 12 watts/channel but it had enough power for my situation. I live in a high rise condo so I can't play my system at extreme levels. I have since replaced the Europas with the Callistos using the same amp. It plays loud enough that one of my neighbors complained when I had the volume turned way up to break in the speakers.