I've worn the same brand (New Balance) for decades. I have wide feet, and there are only a couple brands that can accommodate me - can't even think about wearing Nike, Reebok, or Asics. I know exactly how New Balance fits so I can order online without even trying them on - which is good, because the stores never have the model I want in stock.
Even in my brand, though, the models change from year to year ( which is about how often I buy a new pair) so I always find myself going through the ridiculously confusing process of finding the right shoe.
First you have to decide what you're going to use the shoe for. Training? Racing? Long distance? Mid distance? Sprints?
If you're a serious runner you'll have different shoes for training and racing - and you also probably won't need anyone's advice on how to pick them. If you're a casual runner you'll probably wear the same shoe for training and the occasional road race.
So, for a casual runner the first choice to make is how much cushioning you need. If you put in lots of miles and you tend to plod along, or if you run on hard or rugged terrain, you might want a shoe with more cushioning - but shoes with more cushioning are also heavier. If you run like a gazelle and want to maximize your speed, a lightweight shoe with less cushioning may be better.
The second choice to make is stability. Do you do you have a problem with overpronation or underpronation (supination)? If so, you may want a shoe that offers some sort of motion control appropriate to your gait. If you have a neutral gait, you definitely do not want a shoe with motion control. You can find out more about these and how to test your gait online; here's a quick introduction from Runners' World
The only other choice to make (assuming the shoe fits right) is style. If it looks more like a spaceship than a shoe, it's probably crap.
I'm a serious runner with a neutral gait, who competes at mid distance. I train on concrete but very seldom more than 3.5 miles, and I run with a light step. So, for training I choose a lightweight neutral shoe. That usually narrows it down to a choice between two or three models.
Racing shoes, whether they're road comps or track spikes, have virtually no cushioning and no motion control. Just find a pair that fits.