How loud do you like to play your music?

I try to keep it between 70 and 75 db. An important device to use is a Sound Level Meter. Radio Shack sells a pretty good one. The meter sits next to my remote control. I helps being married to Health & Safety professional.

A lot depends on the recording quality but I generally listen like you around 90 db average most of the time, however, I will crank it from time to time to around 95 - 100 db SPL.

Without you defining a reference track it is hard to say.

Examples of what can be cranked:
Sheffield Labs Drum Track CD (sounds like a real drum set largely because it probably isn't compressed like most all drums that you hear on music that you pruchase)
Dave Grusin Hommage to Duke
Maceo Parker most of his stuff
Tom Petty most of his stuff
Grace Jones Hot Blooded Mix Slave to The Rhythm
George Benson Weekend in LA Live
Mahler and a lot of classical stuff

Examples of what cannot be cranked (too much distortion already on the hyper compressed CD):
Green Day
Arctic Monkeys
Fratellis
Metallica
Red Hot Chilli Peppers
and many many others...

FWIW: A good undistorted clean track with a large level of dynamics can be played MUCH MUCH louder often because the AVERAGE level is low even if the odd peaks hit 105 to 110 db SPL

General listening is between 75 and 82 DB, measured at 13 feet from the speakers. Some music gets played loud, like horn jazz trio that would be experienced loud in a club. Those get 95 DB+ but not for long as I don't want hearing damage.

I measure my system, live music and even restaurants, thanks to a reasonably accurate sound pressure meter in my iPhone.