No. At least not without having everyone look at you. We would understand it, but it would be as if I said "Good New Year" instead of "Happy New Year." These phrases are so well known so you just say it in the one way.
Why do they say ‘merry Christmas’ (in the US) but ‘happy Easter’? I live in Israel, so I was wondering if y’all might have an idea.
They're just all different. There's not really a specific way to wish someone a good/happy holiday. Some have their own special phrase, like "Merry Christmas", but you can't really go wrong with "Happy [holiday]", though it might sound odd for some.
In Great Britain they say "happy Christmas". "Merry Christmas" is a North American English phrase. Perhaps something got confused on the boat across.
"Merry Christmas" is common on the British Isles too, though - just less so than "happy". It even originated in England, so maybe it's not the boat's fault for once. :)
Merry Christmas is normal in Britain.
(answer to comment below)
You said it was common, I said it was normal. Common is not normal! :P