Telegram is the best place I think. It has all the coins and the communities on there. People are joining every day like crazy. I also feel like Twitter is a place where announcements are first made. It seems like it is said there and then on all other platforms coins are on.
True it also become quite a trend lately to talk cryptocurrency there and has become a requirements by some campaigns before you can participate to certain tasks they offer. I think Telegram is a very efficient and friendly platform for cryptocurrency enthusiast and now my favorite one aside from twitter.