This is a difficult one for me because I love music and I like to be open to lots of styles. I am not a fan of today's pop like Brittney Spears or of rap or hip hop. That being said, I will occasionally hear a song in one of those genres that catches my fancy.
I have to say though that guitar is the foundation of my musical taste. In particular, slide guitar takes me to a place that nothing else can. I like all slide guitar but Duane Allman (RIP) played as though he knew how to bypass my brain and ears and go directly to my soul. (I just decided what to cue up on my MP3 player today.)
My latest obsession is Pandora Internet Radio. You can enter a band or artist and hear that band and a lot of others in the same genre. It is a great way to hear bands you already know you like and to get introduced to some new stuff for free. Since they are on the internet, I can go to it on my Blackberry and listen to it everywhere. I have Merle Haggard, Johnny Cash, Waylon and Willie, the Allman Brothers, JJ Cale, The Be Good Tanyas (give them a try sometime) Hounddog Taylor, Muddy Waters preloaded. I can just select one of those and the music starts. If I hear a new band I like, I can add them to my list of stations.