Well probably most roofing companies will believe they are the best roofing company. Of course they will certainly tell you they are the best roofing company to perform your roofing job.
So how do you, the homeowner decide who this company really is? One way is to talk to other people who have used them to roof their houses. But the only way you personally will know which company is best is to try several of them. Fortunately, for most people they will only ever have to use one roofing company. If they still live in the same house twenty years later and have to have another roof put on, if they are lucky they will be able to use the same company as before. Of course, it may now be now run by the son but the name will still be the same.
The way people move around the country these days, you may have to find that best roofing company yourself. If so, your best bet is to get references or testimonials from other people who have used that roofing service. If you found the company online then they will often have testimonials somewhere on their website that has quotes from people who are satisfied with their services. Whether these are actually from their customers may or may not be true. Also no company is going to post letters or testimonials from disgruntled customers. So when you contact the company ask them for some names so you can call them yourself.
References are really the best way to find a roofing company. If you have a house painter come in and paint a room it won't cost you a lot of money but to re-roof an average size house will cost somewhere about $10,000.00. Not the cheapest thing you have to do to your house. And once that roof is on it will be protecting your house for twelve to twenty plus years, or if made from concrete tiles over fifty years.
Maybe the best way to find a roofer is word of mouth. A roofer can't make people talk about how well their roofer performed. So if a neighbor exclaims over a roofer's service ask for their card or their phone number. A satisfied customer is worth a lot of money to a roofer. A satisfied customer really determines who the best company is.