Remington Solar - Our Top Pick 
While Remington Solar SF30-GR is our top choice, there are a few really cool things you should know. Remington Solar also has a 110V adapter which is a plug-and-play device that allows the fan to run on house power when the sun goes down (assuming your attic is still above 80 degrees.) It comes with a humidistat (getting moisture out during summer and winter) and thermostat. It also uses high-performance brushless DC motors. We love their 38V brushless DC motors for the longevity of the motor. Remington Solar also offers a lifetime warranty on parts and components. For this, it's our top choice. The price is also lower than most other national brands. We had a great experience with their customer support as well.
US Sunlight
3 STARS
All in all, not a bad fan. All metal fan. However, this fan uses cheaper brushed motors that need to be replaced every few years. A little more expensive than comparative fans. PROS: Good airflow. CONS: Expensive. Let me just say, we know the solar attic fan market, and these folks have the worst customer service when tested...including their sales department. For that, we give them 3 stars instead of 4. May have to do with their recent purchase by Air Vent. You can find these for sale all over the Internet.
Master Flow
3 STARS
We want to like this fan. We really do. Big company. We like the low profile nature of this fan. Nice how they put the thermostat in their promotional picture. But it's a cheap plastic fan with cheap brushed motors. However, at 750 CFM, it's only going to move about half of the air of a 30 watt solar attic fan. Master Flow, which is a GAF (huge) company also makes the proverbial "Green Machine" sold in some retailers. It's only a 12 watt fan, but it's inexpensive. Brushed motors and a "dome" design makes it a candidate for "most unattractive" design.
Durabuild
2 STARS
Again, more brushed motors. These motors need to be replaced periodically. The Durabuild is an excellent value for the quality you get. This fan comes with a quiet 24-volt motor, an industrial grade 20-watt solar panel that’s thermostatically controlled (it turns on when your attic temperature reaches 85 degrees and automatically shuts off at 65 degrees). Durabuild only offers a 20-watt solar attic fan, and their warranty doesn’t come close to our top two picks. But Durabuild does give you a good value.
Broan
4 STARS
Again, more brushed motors and plastic. However, Broan has been in the powered vent market for years. This is their first attempt at solar. This fan does not come with a thermostat, but can be added later. The price is not bad for this fan, but you're only looking at 537 CFM maximum.
HQST (Renogy)
4 STARS
Aluminum with brushed motor fans. But they look pretty good. This 30W fan has an optional thermostat sold separately. Three metal blades may may this fan a bit noisy. Nice design and airflow. Does not have a way to run the fan at night, but may be ok for sunlight-only operation.
Ventamatic
2 STARS
Ok, we shouldn't have put this one in here, but for goodness sake, but this fan will not win any beauty contests? Only a 12.8 watt panel and a 12V motor, so you'll get a small air flow, but you'd have to put several to match the CFM of some of the other fans. So actually, they're more expensive than some of the other fans on a CFM basis.
Natural Light
3 STARS
Natural Light solar fans use ABS plastic, but have a 25-year limited warranty to back them up. The Natural Light solar panel is adjustable from flat up to a 45-degree angle, or you can detach it and mount it remotely for best sun exposure. You can also purchase a turret extension and tile roof flashing kit for installations on tile roofs. However, they also use brushed motors and is made of plastic. You can get them cheap if you look around.
Attic Breeze
4 STARS
Great fans, but holy smoke, expensive. And they don't even use brushless motors. The brushes in their motors are designed to be replaced after a few years. Are you going into your attic every few years to replace the brushes on your solar attic fan motor? A very expensive fan that ends up being an expensive static vent. They have a very good warranty, which almost gets them four stars, however, we have heard reports of customers not having their Solar Breeze warranties honored.