I'm probably gonna get judged up the wazoo for this, but I've been a diehard fan my whole life. They were the first CD I had, the first band I really got into, the first record album I bought, and have always been special to me. Thing is though, I grew up on mostly their earlier boy band era stuff, and while I still love their later more experimental stuff, their earlier (up to about 1966) stuff is my favorite.
That being said, I'm a huge fan of older music in general, and actually just saw The Who in concert.