We need a chat client - what do you like/use?

Lack-Of is great for long forms and discussions but I want a place to bung links. Right now I have 4 chat windows open. I'd like to rationalise, what do you like to use? Perhaps we could set up a group one?

I quite like Slack - for a number of reasons. Google Hangouts is OK ish.

Pretty much exclusively WhatsApp for everything. I did have various groups of people over Messenger, Hangouts etc, but I think everyone has migrated over to WhatsApp now. Has a decent web interface that not many people even seem aware of (login via barcode scan on the phone camera), and keeps things simple.