I think there's very few people who actively want to be famous. Most of them just want to make lots of money doing something they love, so acting, music, football. The great parties, people sending for freebies, that's a bonus as well.
The fame is the price they pay for these things, not the aim. The people who are famous because they're good at something - The Jack Nicholson's, the Coldplays, the Serena Williams, I doubt any of them enjoy their fame. They don't enjoy being mobbed in the street, having to hire bodyguards everywhere they go.
There's very few people who aim to be famous, and those that do are very rarely actually famous. No-one was mobbing Jade Goody in the street, I doubt Kerry Katona needed a bodyguard on a Sunday morning in Tesco's, and Joey Essex might get the occasional shag out of his fame, but most people couldn't pick him out of a lineup.
The Kardashian s are the only exception to the rule that I can think of. All they have is their fame, that's how they've built their empire. Their talent is fame itself, and that's how they make their billions.