A mixture of thrash, grunge, trad metal and hard rock for the classic games with some occasional ambient. The djent/industrial sound is definitely strong with the id-thesda era stuff but I feel like the harder variants of drum and bass and brostep could work with it (Killer Instinct 2013 drew quite a bit from those sounds and you can't tell me BFG Division isn't just a riddim track with an 8-string and Axe-FX instead of a fucked up bassline filtered through a million VSTs).
Of course sometimes when I play doom I just listen to whatever especially with gameplay wads or wads that don't replace the vanilla soundtrack. WADPAK + 90s production library music is a surprisingly potent combo