I've used wowza and nginx streaming before. If you only want to stream videos, go with nginx pseudo-streaming - I used this module to do it:
http://nginx.org/en/docs/http/ngx_http_mp4_module.html. It is very easy to setup, but its pseudo-streaming.
If you need live streaming, you should go with wowza. You won't be able to stream live videos with nginx anyway, since nginx does pseudo-streaming.