I'm not ASE certifed yet, however, I have been pleased with Valvoline because:
I used the original Maxlife on an old Honda Accord, and it stopped the slow oil leak. 2 years later, several manufacturers copied the idea.
Valvoline was the first full synthetic Dexron VI fluid that was widely available, so when it came out, I bought and replaced the "Dexron type only" PSF in my friend's Scion TC.
I got a great deal on Valvoline Synpower, and my dad's 2.4L Ecotec has never ran quieter.
Valvoline Maxlife ATF works in most transmissions, so one repair center I worked in never needed additives for their Dexron III/Mercon in order to put it into certain Fords and Japanese imports.
I also used Valvoline 75w140 gear oil once in my mom's Jeep Grand Cherokee, but that was because it was the only 75w140 I could find at the time.
I like Valvoline because they make a wide variety of products, are available in many stores, and are priced low.