Rotel for sound quality (accuracy) with NAD another option.
Hafler have a good reputation and should be rugged and reliable but I have not heard them. Alesis sound very harsh to me so I would avoid them.
You can find Rotel and NAD at your local hifi store. Hafler and alesis at your proaudio store. Please do not fall for the stereotype that 'pro' gear is better than 'hifi' gear or vice versa. The main difference is usually pro gear is designed to handle more abuse. Compare specific amps and listen to them driving your speakers.
I would go with a Rotel if sound quality is your priority and you are using it in a home recording situation at reasonable volumes. Probably Hafler if reliability is more important eg being used continuously for 40+ hours a week in a studio or live installation.