@Lash,
I gave links to the numbers of UK-nationals getting EU-citizenship in other nations (as did Olivier.)
Getting the UK-citizenship isn't easy for EU-citizens living in the UK: at first they need a
permanent residence document - there lots of stories that even those living for years in UK and having British children are threatened to be expelled (which is against EU-law). But still, you need to have been living in the UK for at least six years and a bit more.
It costs £1,282 ($1698,49/1.449,07 €) for an adult to apply for in the UK - 250€ (£221,22/$ 293,09) here in Germany