instronics > thumbs up on the metal, and definately check out iced earth if you get a chance, or better yet check out the Wacken Open Air metal festival in germany, always a kickass lineup, last year or the year before they had Blind Guardian as the headlining act!

I tend to enjoy some medium paced techno if I have to write some code or sometimes some the chillout stream on Digitally Imported For chilling out nothing works better for me than some Pink Floyd or maybe Sigur Ros. Actually the only time I break out the metal is if I'm just bs'ing with people on IRC and don't have to actually concentrate, cause a pounding double bass tends to distract me easily.