Here’s one you might not have known you had: tload.
That’s it lurking in the upper left corner, with the simple display of hyphens and asterisks. Not very fancy, but most of the best tools are clean and simple.
You get a graphical display of the system load, customizable only to a tiny degree, and not much compared to what some other system monitors will give you.
But the nice thing is, it seems to be quite common. I’ve checked both Debian and Arch now, and both of them (apparently) have it by default.
So if you’re like me, and you understand load averages but find them quite dull, tload is a little more interesting to look at. Not much, but a little. :)