Wow my musical tastes are very similar to yours.

In addition to just bass, especially in metal I quite enjoy a nice crisp snare sound. Used to love the "Jazz" preset in my 5800XM as it brought out just this feature in music.

The N900 is however very well "EQ'd", the chip can play back a huge spectrum of sounds. Therefore I suggest you go out and get yourself a good pair of earphones. I use Sennheiser CX200 or CX300 or something like that and I'm loving it. Haven't really felt like I need those EQ presets after all.

Don't get those bass amplifying thick plugs, though. I know also Sennheiser have stooped into producing them. They're for simple folk that don't know better. The bass totally muffles out everything else with those monstrosities.