I just finished the entire run of Sym-Bionic Titan which is an AMAZING animated show ostensibly aimed at children, but it is easy to forget that watching it.
I’m also a big fan of Adventure Time and Clone Wars(CGI and 2D animated shorts), I didn’t care for My Little Pony reboot.
I loved both Avatar series Aang and Korra.
I’ve thought about checking out Samurai Jack but am unsure.
I enjoy:
Phineas and Ferb
Fairly Oddparents
Spongebob Squarepants
The Grimm Adventures of Billy and Mandy
I’m a young adult myself, and I also really like Fairly Oddparents and Spongebob Squarepants.
My young adult friends are really into Adventure Time, and they think that it only dresses itself up as a kid’s show but is really intended for adults.
Of course, you can’t go wrong with Animaniacs, Tiny Toons, Freakazoid, or most of the mid-90’s cartoons of that sort. Rocko’s Modern life is bizarre but also good. Who can forget Ren And Stimpy? Were these cartoons REALLY for kids?
Big YES to Samurai Jack. The Powerpuff Girls kinda rocked as well.
Kim Possible
Phineas and Ferb
Fairly Oddparents
The Grimm Adventures of Billy and Mandy
Xiaolin Showdown
Recess
My all time favorite is Fillmore. It plays like the old series The Streets of San Francisco only set in a middle school.
Gulliver (“We’ll never make it!”)
Wait Till your Father Gets Home ("…according to our rules we’ll share it!")
The Simpsons (“DOH!”)
Sponge Bob - I like the Jew-like stereotyping for Mr. Crab. The only stereotyping that doesn’t get my goat.
Pray tell, please do expand on this thought.
The latest Young Justice cartoon is pretty top-notch.
Or better yet, please don’t.
And don’t let the door hit you on the way out.
I still watch the old Nicktoons. Rocko’s Modern Life, The Angry Beavers, Doug, Hey Arnold, Real Monsters, etc.
Already mentioned, seconding:
Spongebob Squarepants
Powerpuff Girls
Adding:
Ben 10.
Dan Vs. which airs on the Hub (same channel as the aforementioned My Little Pony reboot). To be honest, I’m not even sure kids are the target audience, though it’s hard to tell…
Kim Possible
Robotech
Cowboy Bebop
Regular Show - depending on your tolerance for slacker humor. Cartoon Network really likes to misrepresent this show. The previews make it look like nothing but 2 slacker dudes repeating annoying catchphrases, so much so that I would turn off the TV as soon as Adventure Time was over the first month or so RS was on. Once I watched a full episode I was hooked.
Another vote for Grim Adventures of Billy & Mandy. Too bad the *Underfist *spin-off pilot never got turned into a series.
First 3 seasons + the movie for Spongebob Squarepants. Post-movie has been very hit-or-miss.
Pre-initial-cancellation Fairly Oddparents was pretty good. Unfortunately, post-revival (when Poof was added) has been pretty dismal.
Invader Zim always has a moment of two where I think “This was supposed to be a kids’ show?”
The Marvelous Misadventures of Flapjack was a good one once I got past the intentionally ugly designs.
Rocky & Bullwinkle
George of the Jungle and his friends Super Chicken and Tom Slick
A year or two ago I recently re-watched the first season of Rocky & Bullwinkle and thought to myself, “This holds up REALLY well!”
It was a fantastic show. Feckin’ love the fractured fairy tales 
:dubious: Bebop’s a kid’s show in your opinion?
Anything by Butch Hartman, Craig McCracken, or Lauren Faust (who happens to be McCracken’s wife, and has worked on several of his series) is good.
Specific examples:
Fairly Odd Parents
TUFF Puppy
Powerpuff Girls
Foster’s Home For Imaginary Friends
My Little Pony: Friendship is Magic
Super BFF (Part of the DC Nations shorts on Cartoon Network.)
(All but the two in the middle are still running, I believe - FOP may have ended its first run, and I’ve only been catching old episodes for all I know, but it ran a long time.)
Interestingly, Tara Strong had/has roles in all of those except TUFF Puppy (Timmy Turner, Bubbles, Terrence, Twilight Sparkle, and Batgirl).
One thing I like about message boards is one’s (dumb) post can get buried fast after just a couple of (bad) responses. OK, hopefully it’s my last dumb remark.
Kamino Neko:
She’s also on Ben 10, which I had mentioned earlier (she’s Ben).
I agree with almost all of these. In addition, I recommend Teen Titans. (I’m going to avoid Anime for now, because most of the one’s I’d recommend are considered “for adults” in America that are “for kids” in Japan).