Which sportswear brand is better?

Neither, both expensive and wear out quick, you're paying for the name! If you forced me I'd pick Reebok, even though still over priced they haven't stayed in fashion as much as Nike so would be a bit cheaper.

I think Nike is a bit better. However, where I live, Reebok has a jobs program in conjunction with the state and matches folks from the Department of Developmental Services with jobs. That warms my heart, so I try to support the brand whenever I can. 

theyre probably both good brands

I hate them both. Nike refuse to buy from for political reasons so out of the two I would chose reebok if I absolutely had too. 

 For athletic wear though I usually wear lululemon or patagonia. Just personal Preference.