Agreed on many of these. The "Post-Rock" genre, which usually is anthemic and instrumental makes great music for concentrating on intensive tasks. A lot of ambient electronica can be good as well, but sometimes the repetition gets monotonous.

Boards of Canada, Explosions in the Sky, Ratatat, F*ck Buttons, Tortoise, and El Ten Eleven have been in constant rotation for me lately. I often use them as seeds for Pandora as well. Works like a charm.