How to watch dramas together with friends online?

There are a number of services online right now that allows you to watch videos together with a group of friends. Like http://www.watch2gether.com and https://togethertube.com for example.
I was planning on using one of them to watch dramas with friends that are scattered around the country.

Does anyone here have personal experience from using one of these services? Is there any service in particular that you can recommend?
(I need something that allows me to stream something from my computer (preferably), where people can live chat (via text) and that will work for groups from 5 to maybe over 20+ participants.)

Thanks in advance for any pointers!