One can't really say one brand is better than the other as long as you invest a decent amount of money (it's true, you get what you pay for). Much depends on your body type. American brands such us Olympia and Tourmaster tend to be bigger and boxier while European brands such as Revit, Dainese and Spidi fit slimmer types. BMW has all kind of sizes. You really need to try some on to figure out fit because the amor should not move much and it at the right place to protect you. Make sure that you get gear that has good armor, especially a Level 2 back protector, which can normally be added as it doesn't come with the jacket. Then, you need to know if you will be riding in rain a lot. Typically, an integrated Gore-Tex layer or similar is better than a separate layer because you don't need to change and the outer jacket doesn't get soaked and keeps you warmer. For abrasion resistance, leather is always best but has a smaller comfort range in terms of temperature and you would also need extra rain gear. There is no perfect gear out there that does it all, so it will be a compromise.
I few things I would look for:
- avoid polyester fabric, Cordura and Polyamide have better abrasion resistance (cheaper jackets are mostly made of polyester)
- safety stitching
- close fit
- reflective panels
- connector zipper to pants, the longer the better
Sometimes you can get used gear on motorcycle forums or craigslist that is almost new and you can save a lot of $$.