I think Dropbox is great, but I got about 10GB of storage via affiliate links ten years ago and I've never upgraded or paid a cent since. I'm sure I'm a huge loss for them.

And even despite enjoying their service, if Google Drive produced a Windows integration that actually worked well, I'd leave for it in a minute.

I'd never use OneDrive, but that's more out of spite at Microsoft shoving it at me than because it is bad in any way I know of clearly.