long buff raids i love to put some period swing and jazz on, just for that authentic kinda feel (glenn miller, tommy dorsey etc.)
long fighter sorties, lots of stuff really, but usually some classic rock, pink floyd, led zeppelin, the doors, mix and match really.
and quicker paced sorties like mad base defense or a good furball i usually have some more modern dance going
but in general, it's mix and match, if i'm playing music while flying anyway (usually drowns out vox so i dont usually bother)
one thing i cant stand is modern shout rock and aggressive metal crud, which i see lots of people playing along to their vids. i guess some of them get hyped up by it, but i just think it's piss poor...