I use Discord exclusively.
We have one category with multiple channels. There's a voice channel, a dice-rolling/bot channel, a general chat channel, and a "support materials" channel where all the documentation but none of the chatter goes. Support material is used for uploading character sheets at the end of a session, uploading any visual aids/props, and any text from things like journals.
I have used roll20 and other similar tools in the past but prefer to avoid them for my games. I strongly believe that the less things there are to click around on, the better the experience is. Finished 3 campaigns in 3 years, mostly with the same players, and none of them have any major complaints. (Two-Headed Serpent, Cold Fire Within, and Shadows Over Stillwater)