The two main manufacturers available in my area are Owen's Corning and GAF. I prefer Owen's Corning. They have a continuous tar bead on every shingle instead of just spots so there is better adhesion from one to the next. Also, GAF seems to be more brittle after being exposed to the Texas heat, making them harder to repair without doing more damage. All shingles get brittle but the GAF always seem to be much more difficult to work with when doing repairs. I always have to factor in double the number of shingles that are damaged due to additional damage while making the repairs. Not so much with Owen's Corning. When doing a new roofing project I choose Owen's Corning.
While on the topic of shingles: I'm not a fan of the 30 year or "lifetime" architectural shingles. They may look prettier from the street but the extra ridges also hold more debris in a lower pitched roof and at valleys. Also, the extra layers seem to hold in more heat which is a big problem here in Texas and excess heat shortens the life of shingles. In my experience, they don't seem to last any longer than a classic 3-tab shingle. I'm sure there are those that disagree but I can only give my opinion based on experience.