Adventure Time & Regular Show ~ Saw a couple episodes from both, both are alright. I like Regular Show better.
South Park & Family Guy ~ The former is really consistent but nothing I ever loved and the latter was pretty good during the early seasons but nothing ever special and the latter seasons are fucking horrible.
Futurama ~ One of my favorite shows of all-time, love it. Still have to catch up on all the new stuff.
Foster's Home ~ Liked the first few episodes, but nothing kept me watching after those.
Billy & Mandy & Catscratch ~ The former was way too hit and miss while the latter was just meh all the time.
Emperor's New School, Invader Zim, & Chalkzone ~ Only liked the middle one, and outside of Avatar it's my favorite Nick show period. Love Invader Zim.
Lazlo, KND, & Jimmy Neutron ~ Lazlo seemed good from what little I've seen, nice spin-off of Rocko's Modern Life, probably better. KND was great, the ending was such a cock-tease, enjoyed it greatly though. Neutron is good.
Kim Possible & Danny Phantom ~ Liked both, Kim Possible especially. Been rewatching Kim Possible (though not recently) got to episode 20 and I still love the series as much as when I first saw it (if not more).
Jake Long & Lilo & Stitch ~ Jake Long was good but I admittedly stopped watching it when they changed the art style. Lilo & Stitch was only memorable for the crossovers, funnily enough it got paired with the best one here.
Odd Parents & Ginger ~ Meh (though some of the specials [like the internet and channel one] were great) and awesomeness. Loved Carl's stories in ginger. Also had one of the saddest moment in all Nick shows maybe the saddest. I got teary-eyed at least.
Spongebob & Weekenders ~ Weekenders was fun, loved the episode where Tito abandoned all emotion. Spongebob is meh, never really cared about it but never changed the channel if it was on either. Not that good but with it's moments (I hate Spongebob though [found out during rewatch]). Band Geeks however, is one of the best episodes out there for kids programming, it's perfect and almost every way.
All Grown Up ~ Liked it better than the original. Ironically because of nostalgia. Not that I seen All Grown Up first but the series was good with evoking nostalgia like the episode where they found Reptar (one of my all time favorites, up there with Band Geeks for favorite Nick episodes).
Sabrina: The Animated Series ~ Never cared for it, but I didn't hate it.
Samurai Jack & Courage The Cowardly Dog ~ Both really awesome (I love samurai's/swordsmen). Courage's backstory was pretty sad too, got teary-eyed (didn't cry though) when I first saw it. Nowhere near as powerful in rewatch but as a kid it was great.
Hi Hi Puffy Ami Yumi, Teen Titans, & Recess ~ I enjoyed Puffy Ami Yumi way more than I should have but it wasn't anything great. Titans is one of my favorite western animated shows ever and Go! (the show, not the comics based on the show) piss me off more than you can ever imagine. Recess is great.
Pepper Ann, Teenage Robot, & Rocket Power ~ Didn't like Pepper Ann but the other two were great. Though the only episodes I remember from Rocket Power were the dog one, the Tony Hawk one and the video game one.
Static Shock ~ Great, the crossover episodes with Batman/Justice League were beast.
Jackie Chan & Proud Family ~ Loved the first arc (the talismans) but stopped watching quickly after that. Planning on rewatching and finishing it eventually. Proud Family sucks, big time.
Arnold, Bravo, & Ed, Edd, & Eddy ~ The first two were meh and the last one was good but sometimes inconsistent. The last season was pretty weird from what little I've seen, never expected to see them in school. Want to rewatch Ed, Edd, & Eddy some day.
Cow & Chicken, Dexters Lab & Scooby Doo ~ All were good, I don't think I'd like Cow & Chicken nowadays though. Scooby Doo once crossed over with Batman, which makes it the best of them all (and isn't Scooby Doo crossing over with WWE?).
Catdog (I saw the other shows around it but don't feel like commenting on them due to their nature being different) ~ Pretty good. Didn't really like the movie though.
Ren & Stimpy, Doug, & Pinky & The Brain ~ The last one is the only one I really liked.
Rugrats ~ As I said, I prefered All Grown Up but I still really liked Rugrats. Kind of hit or miss but the hits were generally really strong (the misses kill it and make AGU better as well). Also, I liked Kimi, she's a bit of a base breaker but I always liked her.
Rocko's Modern Life & Ahh Real Monsters ~ The former was hit or miss and the latter I hardly remember. I liked it though, and I mark for their crossover with Rugrats everytime I see that Rugrats episode.
Tom and Jerry, Jetsons, & Flintstones ~ Classic but slapstick isn't really my thing (at least not when it's in full force), good, and terrible. Liked one of the SNES games for Flintstones though.