How do you become a citizen of an EU nation?

Question

I would prefer to become a citizen of one of the more developed countries like Sweden, Denmark, Switzerland, The Netherlands or UK but if it is very difficult I wouldnt mind going to another EU member nation. I'm a US citizen and I may be doing part or full time study in the future.

Answer 1

each country member has its own immigration laws you have to go through

Answer 2

you need student/work visa and staying for a longer period to become eligible of applying citizenship or you may marry a citizen of those countries too.

Answer 3

Apply for a job in any EU country and when you had stayed a long time thereat, you could already apply for citizenship in the country where you are working.