People / Companies typically try to go cheap with them.
qwixter: Just get EVGA, and pick the ones with 7-10 year warranties.
The brand is less important than other things but brand comes into play after things like ratings.
https://en.wikipedia.org/wiki/80_Plus https://www.newegg.com/Product/Product.aspx?Item=9SIA2F85FZ3149 More details on rating the better the rating (titanium this case) less likely they are to fail.
This i pointed to is top rating as it gets good brand and considered one of the best.
data centers typically have two psu's each server rack so one fails they can hotswap as reduntancy (replace while system still running).
The rating of psu counts how many reduntancy built into psu .. also lowering of heat which puts wear and tear on hardware.