Computer when I'm playing games and stuff...pretty much everything tbh. And when I'm curled up in bed I like watching videos and youtubes on my phone....sometimes scroll through 9gag and reddit.
I prefer using a computer because it has a bigger screen, physical keyboard, and more programs/apps on it. Although, I will use a tablet or my phone when I am on the go.
I use my Desktop right now more often because it is simply more powerful and easy to use. I am not a fan of the touchpad for a laptop, and I just like having my keyboard, mouse, and monitor separate and not right next to one another.
I find computers and laptops to be more comfortable to browse the internet on than mobile devices. I do occassionally use a tablet or my smartphone, but most of the things I do online are done from my desktop.
I usually use my laptop when I'm at home. When I'm inside the covers of my bed or I'm at my friends homes, I use my smartphone and only when I need it for matters of life and death.