The main beer I seem to recall is Amstel which is I beleive Dutch but could be wrong there. It's rubbish but better than nothing if served very cold. There are others but import costs are higher. Doubtless Guiness will abound.
John, are you UK based? If so then the prices will probably compare to the UK due to the adverse exchange rate, previously it would have been cheaper as I recall, perhaps by 20% subject to where you go.
Lamb and fish are staples in Greece, chips can be hit or miss so go for the salads and live a guilt free holiday.
I too would go with retsina, certaily with starters and light lunch drinks. Not everyone's taste due to the resin but very morish once aquired :)
The generic Greek brandies can be lethal if you are into that sort of thing. And mixed with Ouzo, well
just don't.
If you go sight seeing do not take pictures of aircraft in airfields, any aircraft in any airfield, they do arrest people for spying. Seriously.
One option if you want an all inclusive holiday (activities, food, drink etc
) is Mark Warner or Neilson, they do package deals. Good idea if you have kids as they did good clubs and teach them basic watersports (sailing etc
). We did Kalamata last year with Mark Warner on the Pelopanese and I managed to drop by Sparta and Mystras (Byzantine castle) whilst there.
Steve P