If you regularly run with your volume set at more than about half of full, you might consider a more powerful amp if clean sound is important to you.
The power rating of speakers is typically the largest amp that they can handle, not the recommended size. The efficiency of the speaker is what you should look at (typically dB SPL at 1 m with 1 W of drive). If you search "amplifier power speaker dB SPL" you'll find a plethora of descriptions of how to figure out how much power you are likely to need.
I still run a NAD 310 25-Watt integrated amp and original NHT Super Zeros from the same era and find it more than adequate in my rooms.
NHT SuperZero: two-way, acoustic-suspension minimonitor. Drive-units: 4.5" paper-cone woofer, 1" soft-dome tweeter. Frequency response: 85Hz-25kHz, ±3dB. Crossover frequency & slopes: 2.2kHz, 6 and 12dB/octave. Impedance: 8 ohms nominal, 7.5 ohms minimum. Sensitivity: 86dB/W/m. Power handling: 100W maximum, 15W minimum.
Edited by jeffsf - 11/29/12 at 5:53pm