As some of you remember, I'm teaching online, so knowing thing like if my internet isn't working or there's a memory leak (my Shure mic software went schizoid once), so having a nice easy way to check on things is nice.
I use Rainmeter, it's pretty cool stuff.....this is what I monitor, but there's tons of other things....
My browser tabs are kept just below this so I can see my student/books and see what needs watching at a glance.
Very nice stuff and there are tons of skins.