Currently, to talk to everyone I speak to regularly requires: Skype, Hangouts (multiple), IRC, AIM, WhatsApp, HipChat, Viber, Yahoo!, Facebook Chat...
Because I need 4x hangouts (1 per company I work with, contracting, my own business, personal, etc) and many of the other apps either won't work with other clients, or have crippled features or usefulness, I end up running 10 "chat" clients.
grumpy old man voice Back in my day, we used to be able to setup all our text based messaging in one pidgin client, or a bitlbee instance! Damned kids.