I never spent much time watching NickToons. In fact I think i’ve only seen like, one episode from a few different shows. I was much more of a Cartoon Network kid.
NOTE: this is in no particular order
Doug; I used to watch this show all of the time. This past year while I was around some of my classmates, we talked about old shows and this “Doug Funny” came up frequently. It seems that everybody - everybody - knew and remembered the show. It was nice talking to people with the common interest. But I have trouble remembering: Did the show end after “Doug’s First Movie” came out? I think it did or, at least, it slowed down afterwards. Truly a tragedy as the show was such a hit.
Invader Zim; One word: Unforgettable. I loved this show. Gir was hilarious and Zim was smart and their neighbor was beyond annoying… Man. I miss this show. It’s sad it only lasted one season, but it was pretty good, I must say. I still watch episodes on youtube every once in a while, just to see - if we’re being honest here - Gir.
Hey Arnold; Eek! You could say this was my favorite. It’s still on the “Nicktoons Network” (Channel 126 on Comcast) every once in a while, which is a relief because I don’t remember every episode and I want to. It’s one of those unforgettable shows that you almost have to remember. What bothers me is that it never ended with Helga and Arnold together (you know you wanted them to get together) or with us knowing Arnold’s last name. We did, however, learn the story of his parents and I believe that’s when the series ended. Maybe I missed something?
F.O.P.; I love this show. Love it. I still watch it, with the new baby and all. It’s sort of like “The Simpsons” for a younger set. And I have to say that that’s admirable in a show. The parents are stupid, the kids vary, and it hasn’t a real point. Plus, the fun characters - Cosmo, Cupid, Jorgan, Chester, etc. - are always fun to see.
Rugrats; Even though I hate the spinoff, Rugrats is an amazing show. Growing up in the nineties, I knew and loved this show. Sure, it was based off of kids in diapers going on unrealistic adventures with their huge imaginations, but it was fun to watch. It’s like TV fluff, if you know what I mean. It’s just a show you can watch whenever. If you see it on the TV guide, you change the channel. When there’s nothing else on, Rugrats is there. I just wish it was on more often.
Spongebob; I really like the old episodes of Spongebob where the coloring is bad, the script is rough, and the show sometimes has an actual point. Lately it’s not so great. That’s all I have to say on the matter.
And, of course, Jimmy Neutron, Ren and Stimpy, Catdog, Angry Beavers, and all the rest. I think it’s safe to say I grew up on Nickelodeon.
Avatar: The Last Airbender is my ultimate favorite NickToon, hands down. 
Five stars for Avatar!
Haystack
i love Avatar…watched it all the time…i alos used to watch other show that were on. Anything…now that i’m into high school not so much.
Ditto. Too bad the series ended a little while ago. 
Haystack
I loved Nicktoons in the 90’s! Top 5 would be this:
- Angry Beavers
- Doug
- Rugrats
- Hey! Arnold
- Spongbob… gotta love him!
My top five favorites (in no particular order) would probably be…
- Avatar
- Rugrats
- Hey Arnold
- Angry Beavers
- Rocko’s Modern Life
And so many more…
For some reason I have a feeling I’m forgetting one of my most favorite ones. xD
fairly odd parents, sponge bob??? there every one’s favourite. or what about Jimmy Neutron. I suppose I’m just thinking about the one’s that I like. but there are some you didn’t have on your list. 
I liked avatar as well. I thought it was a cool show, how they combine kung fu with powers of manipulating the elements.
Oh yeah! I knew I was forgetting some! I used to watch Fairly Odd Parents with my sister all the time.
glad I could help.
OKAY! OKAY!!!
I am so much more obsessed with actually good nicktoons since I found this old CD I forgot I had! I rediscovered a lot of old forgotten favorites of mine!!! In fact, I’m listening to some ‘As Told By Ginger’ songs right now!!!
My NEW all-time favorites:
[i]10. AHHHH! Real Monsters!
9.Ren and Stimpy
8. The Wild Thornberrys
7. Rocket Power
6. Pelswick
5. The Angry Beavers
4. Doug
3. Invader ZIM
2. As Told by Ginger
- Hey Arnold![/i]
My favorite Nicktoons
- Spongebob Squarepants
- Avatar: The Legend of Aang
- Jimmy Neutron
I would have to say…
1) Avatar-awesome storyline
2) Danny Phantom-because its directing by Butch Hartman
3) Jimmy Neutron-well because it funny
4) SpongeBob Squarepants-do i have to explain… 
5) Fairly Odd Parents-again Butch Hartman
5.Rocko’s Modern Life
4.Spongebob -…the first three seasons mainly. And also mainly for Plankton
3.Ahhh! Real Monsters
2.Rugrats - first runs only, not the new eps with the baby bro, Dil, was it?
1.Ren and Stimpy -Because John K is my animation God!
Plankton is awesome!!!
Yo, COLLEGE student over here…watching Spongebob at 11PM at night as I type…but hey, maybe it’s just me…kid at heart, animation enthusiast, etc.
By the way, If you REALLY listen to what is said in shows like Spongebob and Fairly Oddparents, etc. there’s plenty of inside jokes to go around…
Just my 2 cents on the matter…
I’m in high school and I watch nick all the time xD,
I love the inside joke in the fairly odd parents summer movie
“I’m the president of kid world??!?
Everywhere but Florida, they’re still voting!!”
Top 5:
- Avatar, hands down, bar none. Amazing storyline, very mature, I love creating the history behind it(I can tell you exactly what happened to cause the seperation of the nations and why only firebenders have metal weapons and such).
- Spongebob, it’s so random and funny and quotable that I can’t help but love it.
- My Life as a Teenage Robot-I wish this one didn’t get taken out of the regular nick station, I just think it’s funny watching someone trying to fit in at high school and ot failing horribly.
- Danny Phantom, which I can’t really say a reason, it just attracts me.
- Fairly OddParents because I really like the story of having everything you want at your fingertips, yet never really being happy.
Hey Arnold is probably my favorite Nick show. It was edgy, hilarious, and it had some amazing heartfelt moments, especially in the Christmas special and the episode “Parent’s Day”.
Avatar’s great as well, especially when compared to most “recent” cartoons. The characters are extremely well designed, the plot is solid, and it’s exciting. Not to mention the wonderful soundtrack; my favorite song is probably the song that plays during the final scene or “Leaves From the Vine”.
Danny Phantom has a special place in my heart, because it was my first real fandom experience. I like Spongebob before it jumped the shark. Invader Zim is quite win as well.