How Can I Tell My Friend She's Annoying? (In A Nice Way)?

Okay, so my friend is really annoying. How do i go about telling her? She always talks about the most stupidest and pointless things and many people at our school dislike her. Most of the time she goes on and on about the boys she likes but can never date. It drives me crazy! UGHHH! She says "oh everyone hates me" in order to get sympathy.