I think, with Linux Distros, it's not about some list, but about you! Do you like Mint? Why do you want to change away? What are you looking for in a Distro? If you can answer this question, it is way easier to find another Disto to test.
I've heard Debian is at the top but its alot more advanced
Not really... Mint is based on Ubuntu and Ubuntu is based on Debian, so you already have a flavor of a flavor of Debian 😂 However, if you do like the apt package manager, you might go for Ubuntu or Debian to see the differences.
Keep in mind, though, that a distribution mainly consists of the very low-level stuff. You should change the distro if you don't like the package manager or how the base-system is managed or if you don't like a Distro's politics.
If it's just a part of the software on top, you can stick to your current Distro and change parts and pieces to see if you can get a better fit. For example, if you don't like how your Desktop behaves, why not change out the DE? Use KDE, give Gnome a try, have you heard of Cinnamon? Many people use MATE... etc.
However, if you want a wildly different flavor of Linux, I recommend going for a non-Debian based Distro. For example, give Arch Linux a spin, you will learn a lot in the process! Since you want to be productive, try Clear Linux. They say it has the best performance of all binary distributions. Or, if you really want to dive into what Linux really is, you can go for Gentoo, Slack or even LFS - they are hardcore, but you will know how to turn every knob of your system in order to customize it your way.