Best 4Kids Arc
 

Best arc in the series?

Return to New York.

I completely misunderstood the type if thread and wrote something completely inconsistent.
YES.

Space Invaders
 

Space Invaders

The Shredder Strikes Back episodes were the first ones that had me on the edge of my seat, and saying to myself "holy $hit, how is this gonna play out?". And then those episodes were followed up with Return To New York, The Search For Master Splinter, Turtles In Space, and Secret Origins. It's like for almost 18 straight episodes, the show had me constantly watching to see what was going to happen.

One of my favorite moments in all of 2k3, is when Leo says: "We can sure as SHELL save that old lady!"

It was one of those just... "YEAH!" kind of moments.

Shredder arc (first season), Turtles in Space and the Battle Nexus.

Battle Nexus, RTNY, Rogue in the House.

I’ll echo this. I was watching episode after episode from high quality (at the time) TV rips that I was grabbing from IRC. Full on 640x480, baby! I was blown away how invested I was in the story and how it just kept going full steam ahead. In fact, I still have those episodes burned to CD. 17 or 18 years ago at this point.

The follow up arc World's Collide is better.

I said that wrong. Return to New York is one of my favourite three-parters in the series.

Agreed. And I had only seen bits of seasons 1 and 2 when the show originally aired so watching the episodes in the right order a few years ago was a much more enjoyable experience.

I think my favorites are Notes From The Underground, Return To New York, Search For Splinter, Secret Origins, Space Invaders/Worlds Collide, the Ultimate Drako one, Exodus, Good Genes, Enter The Dragons.

Favorite has always been battle nexus

Another vote for the Battle nexus

Favorite: Battle Nexus

Guilty Pleasure: Ninja Tribunal (I like ninja magic)

Turtles in Space because it has a cool space adventure arc that spans 5 episodes.

It's been too long but I always like the episodes that feature smooth and detailed animation. I'm pretty sure it was Shredder Strikes Back or something that used to please me. Or maybe Return to New York.

And then I'm pretty sure season 3 or 4 had the animation sort of hitting it's stride. I remember those episodes looking better, am I crazy? Hun on the Run had cool fight scenes and I thought one of the episodes where one of the turtles was a rampaging beast looked pretty nice.

Fugitoid war (Space Invaders + Worlds collide)

Battle Nexus, I suppose.

But I also like Secret Origins. Shredder's revelation as a Utrom was quite big back in the day. Remember the controversy it caused?