I can't add much to what Alan said.
I routinely watch DVDs around the -20 to -15 mark on my Denon 3808 and music is around that -24 mark.
Those 90W/channel are only needed for peaks in the music/movies on average it only takes 1 watt to achieve 89-93 db depending on your room, that is what the sensitivity specifications means for speakers. The more sensitive the speaker, the easier it is to drive them or make them sound loud. Most people find 75-85db to be about normal to slightly loud listening levels, which translates to actually only needing less than 1W to make them hit those levels. There is a whole thread on the board about dynamic range and the power requirements needed to hit high SPL and some links are thrown in there to some power calculators.
For example, I would need 159W/ch to achieve 100 db(loud) at my seat(2 meters away from speaker) with out distortion from my M22s with music having a dynamic range of 10db. I need 126W/ch for my M80s.
