Q is the only music magazine I read on a regular basis because it seems to be more directed at real fans, not just top 40 followers (like Rolling Stone and Spin) and not High Fidelity-esque fans (like Mojo). The interviews are interesting and original, they give equal coverage to legends and up and comers, they realize that music does have a past that should be acknowledged, and they have really great writers working for them. I've never really read Blender, only that little number thing Edge was interviewed for. I am very excited about what Alan Light's (former Spin editor) new music magazine is going to be like, the US is in desperate need of a smart yet accessible music magazine written by people who are actually fans.
Hot Press is also great, but it's more general pop culture/society than just music.