How much power/channel for multi-channel amp?

First of all, thank you for reading my post. I have a fairly good Denon AVR 2802, which will be used as pre-amp. As for the surrounding speakers, I love those AR Phantom speakers. The handling power is from 50-250 watt with frequency response from 40Hz-20KHz. I am currently interested in a multi-channel amp. What is the handling power per channel do I need for a normal reasonable movie listening and viewing? Is 80 wpc a good recommendation? Is 100 wpc the standard? Is 200wpc the ideal? I like to take a poll to see what amp power do you have, and if it is more than what you need. My idealistic goal is to spend the money efficiently, i.e. to spend enough money for the power that I need -- not more not less but just right. Apparently, I won't blast the speakers even though they can handle it up to 250w. Besides, the I won't have enough money to acquire a 200wpc channel multichannel amp to test my speakers. Any comment will be truly appreciated.