Some of the fringe metal stuff described above wanders through my playlist - Disturbed, Three Days Grace, Breaking Benjamin, Rob Zombie, etc. - but it's more the passing song than any strong feelings about the genre.
I generally fall into one of three very different music styles at work. If it's a slow day and I don't have any pressing deadlines, I will listen to native tongues-like 80's and 90's jazz rap. So mostly that's:
Digable Planets
A Tribe Called Quest
Us3
Digital Underground
Early Outkast
Early Public Enemy
Beastie Boys
Queen Latifah
Newer stuff in the same vein would be like Macklemore, Lupe Fiasco, and B.o.b. EDIT: Somehow completely left off the list my love for Eminem.
On days when things just have to get done or I don't want heads popped into my office door, I'll lean more into punk rock. My favorites are:
Offspring
Rise Against
Dropkick Murphy's
Flogging Molly
Green Day
Black Flag
Bad Religion (ironyusa, you'd probably have a really hard time with my music selection man)
The random stuff that falls in between is mostly california rock and seattle sound:
Silversun Pickups is one of my favorites of any genre
The Head and The Heart
The Avett Brothers
The Decemberists
Plumb
Lana Del Ray
Paramore
Jason Mraz
Tristan Prettyman
CSNY
Beatles
Paul Simon
I'm sure that seems like it's all over the place, and believe me it has taken months of hammering away at Pandora so it can understand how to move seamlessly from The Choice is Yours to The God Song.