Basically photoshop and games. I was dual booting and when I switched computer it wasn't worth reinstalling because I spent most of my time in windows. This was a long time ago.
Now that windows is moving into subscription basis I keep thinking I should try getting into linux again but I don't have the time to fiddle around making stuff work.
Apart from Steam I mostly use consoles for gaming these days so it would only be Photoshop I guess ( I think ms office works on Linux now?). Gimp is cool but it still can't do everything photoshop does and I find the GUI counterintuitive.
The one thing I still do use Linux for is booting with a thumbdrive when a computer running Windows has a meltdown.