Batman the animated series
Avatar the Last Airbender
Gargoyles
Puella Magi Madoka Magica
Cowboy Bebop
Fullmetal Alchemist Brotherhood

In my opinion these are the greatest cartoons and anime of all time. There are plenty of other great shows, like Death Note, Superman the animated series, Justice League Unlimited, the Simpsons (only lest off the above list because the later seasons aren't as amazing as the first 10). While I have a nostalgic love for DBZ, there are plenty of cartoons and anime which I think are better.

I know its very popular and not a hidden classic but have to say I love 'One Piece'. After going through many episodes though the interest started to wane a bit as they ran out of fresh ideas but really like it. The other anime I really like is 'Desert Punk' it just really works for me. Then Gunslinger Girls although part of the appeal is the brilliant intro sequence and music. I got bored of Cowboy Bebop quite quickly but still come back to it occasionally to watch another new episode to me. I'm not the greatest anime fan though a lot of it turns me right off especially if it simply steals ideas from elsewhere and I feel its been made by the numbers for commercial reasons and has nothing fresh of its own.

Bible Black, great story and lots of action!

Good taste, Ergo Proxy is god tier.
Kill La Kill is pretty fantastic too.

My Hero Academia is pretty good and it's still on-going. Starting to really like it. I hope they keep making a decent amount of episodes for it.

Adventure Time? sure it has a more lighthearted tone, but it as whimsical and lore heavy as you could ever ask a show to be.

Avatar: The Last Airbender.

The fact that it's all packaged into a kid friendly end result just makes it even more impressive.

I still watch most of the cartoons I watched when I was younger in the 90s and early 00s. Apparently there has been a resurgence of great cartoons with Adventure Time, Gravity Falls, and Regular Show but I haven't watched them yet. Are there any other older members here who enjoy the new cartoons?  Which should I start with?

These are some of my favorite animated series, which I consider better than Dragon Ball Z and Rick and Morty:

Avatar: The Last Airbender
Cowboy Bebop

Hey Arnold

Samurai Champloo
Samurai Jack
The Simpsons (seasons 1-8 and a handful of episodes after)

Let's see, Cowboy Bebop, Fullmetal Alchemist: Brotherhood, Death Note, Avatar: The Last Airbender, Lengend of Korra, OG Teen Titans and Samurai JacK are up there.

Rick and Morty is absolutely brilliant dude, don't talk about low standarts when every of your recomendatios is clearly worse.