OK, please don't hate me for this. I don't hate ALL Gryffindors. I just think the House itself is over-rated.
All the Weasley's were in Gryffindor. As they are the nicest people in the whole book, and love Harry, people love them. Therefore they love Gryffindor.
Gryffindors basicly owned Hogwarts when Harry's parents attened Hogwarts. James and Sirius mocked the living hell out of Snape, while their two allies looked on. All four of them just happen to be Gryffindor. Weird, hey?
Isn't it a bit unfair, while Harry and co. were at Hogwarts, the head and deputy head were both Gryffindors. And twice...