When I needed to get my roof done I worked thru Home Depot. I figure they have been around for a while, have local presense and should be around for a while more in case I have problems.
I talked to a few independents, and was scared off.
I ended up paying more, but I bought 50 year shingles (fiberglass architectural) which will last me for the rest of my life. HD also has a labor guarantee. And financing.