To provide an answer to your question, I'd have to know more about your life style, needs and budget. Having said that here is some information, hope you find helpful:
You can find excellent elementary schools in all three areas you've mentioned above, But if you consider high school, then everygreen is out of the picture. Alamaden valley does have Leland which is a good school and you'll have to make sure you will limit your search in specific neighborhoods that feed in to leland high. Cupertino, for most parts, you'll get great schools at all levels.
Age of homes: Evergreen has the new homes (average age), then Almaden and last is Cupertino. this is not say you cannot find newer homes in Almaden and in Cupertino, but the cost will be higher
Pros and cons: For this I really need to know what price range you're talking about. But here is a quick note on each area:
Alamden is beautiful, quiet but its a bit further from "silicon valley".
Evergreen is also nice, but its not at green and it gets hotter in the summer and commute is somewhat heavier.
Cupetino is centrally located but a bit more crowded.
I'd be happy to discuss this in more details with you over a cup of coffee :)