Adventure Time: For me, it was at it's best when it was still fresh. Now it seems too self-aware of what works, and it keeps on pushing at it, often times a bit to hard. It feels like it pushes the envelope less to do something meaningful, and more just to make you go "Wow, On a KIDS show?!?". It's much more irresponsible and loose than Regular Show, which is anything but..
When it works, it is great, though.
Regular Show: I feel like they've accepted their world, and have learned how to flesh it out constantly and consistently. It's animal and human characters interact as naturally as such a mix would in old 80s cartoons. It has a serious nostalgia-bend, but it's more to honor it, rather than just to exploit it for attention. And as mentioned earlier, it does a great job at treating relationships very well. Even someone as hair-brained as Rigby ocassionally calls himself out on the quality of his thinking, and characters often admit and deal with the things they do wrong. It's one of the most refreshing things about the show, and better than most animation of any type, in that regard.
Steven Universe: This show is so odd. I never find Steven annoying, he's always good at toting the line of being childish, and yet likable. He's truly the heart of the Gems. I want the show to be a bit more action-focused, because the idea of 4 powerful beings just... hanging around town all the time seems like a bit of a waste. I find it hard to believe Steven hasn't figured out his power, and what to do with it, yet.
But it's not really needed. The show takes the mundane, and makes it fun, in a fresh way for an American animation. And some of it's music really makes it feel like the first time I'd seen Laputa, Naussica, or Sailor Moon; beautiful and very "girl fantasy" friendy, and completely true and understanding to their audience and subject matter, yet full of quality.
Uncle Grandpa: Irresponsible and Stupid for the sake of Stupidity. In a way, I feel like it's a failed attempt to channel all the Canadian animation shows and shorts that Nick had back in the 80s/90s, but with horrendously bad execution. I don't like anyone on the show. There's nothing to feel good about, it's all just a quagmire of "eh". The show constantly seem to have no theme or direction, it just throws out situations without any reasoning. My least watched of all the shows.
Clarence: Why does LSP look like a boy, and have her own show?! I kinda like the fact that the show seems to take a boy who I'm sure would be the center of jokes and bullying, and make him into someone everyone seems to generally like. But I don't feel like it gives me anything I'm not already getting out of the first 3 shows.
Teen Titans GO!: I really WANT to dislike this show, and scream "GIVE ME BACK MY REAL TITANS!"... but it's way too much like watching SD parody of one of your favorite series, with all the important original talent in tow. It's fun. It's appropriately self-aware. They seem to well embrace everything there is to love and hate about the show, and work with it. Which reminds me of how I felt about the old TT show.
The Rest" Johnny Test reminds me of American Dubs of anime, with it's overuse of sounds, wordfit-to-fill-every-moment-with-speech dialog style, overly-hammy and gross jokes as if they HAVE to make up for the look of the show with equally lame writing, and just being annoying in general. -- TMNT 2012 Is great whenever I see it, and sems to respect the property. -- I kinda miss Flapjack and Chowder. -- Gumball actually kinda pleasantly suprises me every once in a while, but I get tired of seeing those kids running around nude or such. SO MANY STYLES in that show. I like it more than I expected to. -- I've never seen Gravity Falls at all...
That's a lot of cool interesting weird awesome Dandy.