I loved Dexter's Lab, Powerpuff Girls, and Scooby Doo. Cow and Chicken actually freaked me out -_-
Dexter's Laboratory was probably my #1 favorite.
Scooby Doo wasn't a Cartoon Network-original show though. Scooby Doo aired on other channels way before Cartoon Network ever was a thing. Sorta like how Looney Tunes wasn't a Cartoon Network show.
Of the ones listed, Courage the Cowardly Dog is my favorite. I enjoyed all of these though, with Ed, Edd n Eddy and Dexter's Lab probably being in 2nd and 3rd.
That said, since Courage the Cowardly Dog and Ed, Edd n Eddy barely count as 90s shows since they debuted in 1999, I'll also mention Grim & Evil/The Grim Adventures of Billy & Mandy as another favorite despite it not debuting until 2001.
Powerpuff Girls, baby!!
... Not the reboot, obviously.
how can you mess up courage the *cowardly dog? and yeah that one's my favorite from this list, though I grew up watching more 80's cartoons