I've been a happy customer of Tresorit for several years now. Give them a try if you're fed up with Dropbox.

At first I was selective in what folders I synced but after a few months I decided to just sync my entire workspace folder with everything in it.

Incredibly convenient, everything is automatically synced between my desktop and laptop.

If you go this route look into filters, it's not a very advertised feature but works great for excluding build output, venvs and other stuff.