Both Plesk and cPanel are solid options, but it really depends on what you're looking for.
cPanel has been the industry standard for a long time — super stable, widely supported, and most hosting providers are already familiar with it. It's Linux-only though, so you're limited in that sense.
Plesk, on the other hand, supports both Linux and Windows servers. It's got a cleaner UI (especially for beginners), and it's very developer-friendly if you're working with things like Docker, Git, or Node.js.
In terms of demand, cPanel is still more popular overall, but Plesk has been growing steadily — especially among users who want more flexibility or are managing WordPress-heavy environments.
If you're running a typical shared hosting setup, cPanel might be the safer choice. But if you're doing custom VPS work or need Windows compatibility, Plesk could be the better fit.