In reply to:
A good company like Denon, HK, Onkyo, and Yamaha will offer lower numbers, like 70 watts per channel, but they are a real 70 wpc RMS, which means continuous, not peak.
Small nitpick: RMS isn't continuous, but average. It's taken from dividing the integral of the signal over one period by the period itself.
/EE geek mode off.
Sadly, there aren't many specs at all one can reliably look at to determine the performance of a A/V equipment. The specs don't really tell much of a story as there are far too many variables involved and the ultimate goal, pleasing sound, is entirely subjective.
I recommend picking a price point you're comfortable with (the stuff at Circuit City and Best Buy is all crap to my ears...) and auditioning the models in your price range (in your home if you can). I actually swapped out the top of the line Yamaha model Best Buy carried in 98 or 99 with a Denon AVR-4802 last month (price jump from $649.99 to $2100.00) and almost wet myself the first time I heard it.
Listen to them all, and determine whether or not your ears can tell a difference. Then determine which differences you prefer.