I'm sure many members will comment on this question. By the way, if we don't question, we don't learn

IMHO, it's not so much the make that is important but the freshness of the spices. Always buy small quantities, which means that they'll be used up fairly quickly and replaced with fresher. This is most important with ground spice. Whole spice keeps a lot longer than ground. Keeping spices in the dark and in airtight containers will help maintain their condition.
I won't even begin to comment on garam masala. There is loads of discussion as to when it's used, if it's used, should it be used, which type, what it is, what it does etc. etc. You can read many of the threads at your leisure.
As for spice brands, the most popular ones tend to be Rahja, TRS, East End and Natco. Some restaurants may prefer certain brands. The Ashoka thread contains a preference for East End. Some purchase based on price alone, with Rajah being the more expensive. Not sure whether this helps but i'm sure others will chip in.