I would go with arch linux if you are bored. You will learn a ton while installing it, and the install guide is very easy to follow. Because there is no guided installer, you will have to learn how to mount, partition, and format filesystems from the command line, which is an invaluable skill. You will also have to install a bootloader, etc, and the entire process takes place on the command line. Back when I started, completing an Arch install felt like a great accomplishment. TBH I fell like a default arch install is pretty stable, although you will likely run into issues. That being said, debugging problems is how you learn. I used ubuntu for about 2 years, then got bored, then used arch for about 2 years, and now I am using gentoo. Eventually, I may use slackware or openbsd.