I am building isomorphic apps with React and I always use react-router. Didn't know about Uniloc (as suggested by @fibric), which seems to be a universal route parser in JavaScript. I am not sure how Uniloc handles nested and more complex UIs. But I feel react-router is still a great solution for all your routing needs.
React Router was initially inspired by Ember router, so if you are coming from an Angular background it may be difficult for you to wrap your head around the concepts initially. However, if you are looking for a router that's simpler and resembles ngRoute (to certain extent), try out react-routing written by @koistya. I have never tried it out, but looks promising.