Rammstein makes sense. I suppose my preference for the loud stuff at night comes down to stimulation and energy levels. Never actually thought of it in that way until now, thanks.
For me it is very related to what I need to do. Wringing out 1000 LOCs in a day -Nitzer Ebb, Ministry and Rammstein it is. EBM in general is really helpful. And interestingly this specific song by U2: https://vimeo.com/41133252
I apply one more trick, that I got from some self help book once: my energy level is not always the same, and too little energy is a problem for concentration but so is too much energy. If it's just right, I'll likely be able to find the flow and then the music matters less.
Rage Against the Machine and Rammstein can improve energy levels. Very quiet music (current favorite Carrie & Lowell by Sufjan Stevens) can quiet me down so I can concentrate.