It's "Gee, Brain".

"Same thing we do EVERY night, Pinky. Try to take over the world."

(Actually, I've never watched a single episode of this. I only know the theme song because several years back, one of my friends pulled a few all-nighters for a Carnival project called Booth, in which a student org builds a one-to-two-story booth/house as an exhibit. When she finally finished, she was a bit... delirious... and started sitting in a corner, singing to herself.)

The two that are left. One is a newer show, the other is about 15 years old by now.

And I'm guessing I've probably never watched either of them.

Ooh! One left!

A boy and a snake... Mhmmm...

Bingo! That's all of them!

Quiz 2 will be posted in a minute or two!

edit: Quiz posted! I will be going to sleep soon and will prepare Quiz 3 and 4 later. Good luck!

Okay, let's see...

1. This boy lives in a home with his 10 crazy sisters.
The Loud House
2. A girl who must defend humanity from monsters that only she and her grandmother can see.
? (no idea, but sounds like a show I'd watch)
3. A strong man must fight a evil skeleton warlock and defend his kingdom.
He-Man and the Masters of the Universe
4. Two rabbits, a sister and her quite brother live life together in this childrens show.
? (I'm thinking Looney Tunes, but can't recall whether the female was Bugs Bunny's sister or girlfriend)
5. A famous duck goes off with his pig sidekick into the cosmos seeking adventure.
?
6. Five warriors must combine their five mechs in order to fight invasive alien warlords.
?
7. Three siblings who deliver in their master's food delivery service must collect pages of a magical cook book.
?
8. A Japanese warrior was thrown into a future by a evil warlock and must get back to the past.
Samurai Jack
9. This show stars a girl and her days at school, in this strange photo cutout show.
? (going to say Lizzie McGuire just for the photo cutout hint, even though I think it's way more live action than cartoon)
10. A group of friends upload themselves to a video game like world in order to protect the world from a evil computer virus.
? (don't know, but once again, would watch)
11. An annoying coconut living on a island with other fruits.
? (and now I have the Sponge Bob theme song stuck in my head XD)
12. These kids are secret agents who protect kids from evil adults.
? (unless vampires and grasshoppers qualify as secrent agents, then I might have a vague idea)
13. Two angry rodents live in a dam.
?
14. A scared dog must defend his family from the supernatural, aliens, and all things that go bump in the night.
Courage the Cowardly Dog
15. These two martial artist bunnies give evil a wedgie.
?
16. This team of a human and his robot monkey friends defend their city from evil.
?
17. This hamster goes around having fun with friends.
?
18. This show stars a 11-year old who loves a boy ninja.
?
19. A teacher takes her classes on many amazing field trips.
The Magic School Bus
20. A group of ragtag kids just trying to have fun in their schools playground.
Recess
21. These girls are part of a cat-like band handled by their not too dependadable manager.
Josie and the Pussycats
22. A bear tries to steal picnic baskets in his home, a state park.
The Yogi Bear Show
23. An American man wins a contest to star in a popular Japanese Action show.
?
24. A popular video game character protects an island from a evil egg shaped villain.
Sonic the Hedgehog
25. These kids are pirates who spend their days competing with a famous pirate.
? (My first instinct was Peter Pan, but the Lost Boys aren't actually pirates, so...)

Wait, is this western cartoons only, or is anime included?

Well, since Death got most that I knew...

13. The Angry Beavers
17. Hamtaro

Espy: I believe it does include anime.

I feel like I know a few of these, but my brain's not cooperating.

25: One... Piece...???

It definitely includes anime, and now that you mention it, I've even watched a few episodes of One Piece. Still, sounds to me just like Peter Pan... somehow vaguely fitting the description, but not quite. But maybe that's just me picturing "kids" be more around 8-12 year olds.

Awwww... I wanted to play.

You still can. There's several shows that haven't been guessed yet ^^
Reposting unsolved clues for Ari (and anyone else who wants to try)

2. A girl who must defend humanity from monsters that only she and her grandmother can see.
4. Two rabbits, a sister and her quite brother live life together in this childrens show.
5. A famous duck goes off with his pig sidekick into the cosmos seeking adventure.
6. Five warriors must combine their five mechs in order to fight invasive alien warlords.
7. Three siblings who deliver in their master's food delivery service must collect pages of a magical cook book.
9. This show stars a girl and her days at school, in this strange photo cutout show.
10. A group of friends upload themselves to a video game like world in order to protect the world from a evil computer virus.
11. An annoying coconut living on a island with other fruits.
12. These kids are secret agents who protect kids from evil adults.
15. These two martial artist bunnies give evil a wedgie.
16. This team of a human and his robot monkey friends defend their city from evil.
18. This show stars a 11-year old who loves a boy ninja.
23. An American man wins a contest to star in a popular Japanese Action show.

Your getting super close.