Trane
Trane XL15i AC
The best unit on the market.
Lennox
Lennox XC17 AC
The XC17 is the quietest unit, and comes in all sizes.
Amana
Amana ASX14 AC
Amana offers a lifetime unit replacement warranty and a 10 year parts warranty.
Goodman
Goodman GSX13 AC
The most cost efficient and affordable unit.