Pump up the volume - metal/rock/punk does it for me, Rammstein, Metallica, Iron Maiden, Green Day, Stone Sour, Alter Bridge... Or, occasionally, I'll go the other extreme and wind down with Clannad, Pink Floyd, Judie Tzuke etc.
If it's really bad then I take it out on my guitar playing much as mentioned above, or Rock Band drums :)
Basically, just do something you like. Go for a walk/run/cycle in the sun (or rain for that matter) in the park, or woods, by the river, wherever. Or take time to play with your children (especially if they're young).