Pros
Riot is a great place to work. The company really takes care of its employees, office is awesome, and there are many awesome perks such as free food and drinks, great equipment, international travel multi times a year, company retreats and more. The culture is also amazing, people are really encouraged to give candid feedback and help you grow and develop as a professional. And of course, if you're a gamer, this is your place to be. Riot live by it's philosophy of being the most player focused company in the world, meaning you have the autonomy to create great things that players will love, and see your work impacting people around the globe.
Cons
Work-life balance is nearly impossible, I'd say. Specially if you're working on some specific areas such as eSports and live shows, you'll be away from home and working around the clock a lot. Rioters working in regions outside the HQ in Los Angeles are seen as second class citizens, which is not nice at all.