OK, I'm just going to out-and-out say it: Great cartoon shows are getting cut down too soon in their runs.
Now, I'm specifically referring to cartoons based on comic books right now, because that's pretty much about the only new cartoons I watch anymore. Oh, and I'm going to focus on DC cartoons, because about the only Marvel cartoon that I'm aware of right now is the Super Hero Squad Show, and only 40 episodes of that aired on Cartoon Network (although apparently, 12 more episodes were made and aired on other channels). Oh, and just for the record, the 1967 Spider-Man had 52 episodes.
The various incarnations of Super Friends had 109 episodes (and don't forget, many of those were hour-long episodes).
The original version of the Bruce Timm "Batman" cartoon lasted 85 episodes, and had another 24 episodes as "The New Batman Adventures." So about 109 episodes.
Batman Beyond, which could almost be seen as an extension of that series, lasted 52 episodes.
Superman: The Animated Series had 54 episodes. Heck, the Filmation Superman series had 68 episodes!
Batman: The Brave and the Bold? 65 episodes (although it doesn't even feel like they aired that many).
Justice League had 52 episodes plus 39 episodes of Justice League Unlimited (i.e., 97 episodes).
The Legion of Superheroes TV series, sadly, only had 26 episodes.
Teen Titans had 65 episodes.
So yeah, these days it seems that 65 is the magic number at which they end shows. It doesn't matter how popular they are, they're just going to end them. What's really stupid about this is that often, it's in the final season before there's much merchandising done!
And none of this seems like enough... I know I wanted more of all of the above shows!
OK, let's look at it another way: Every single one of those shows were based on comics that ran for years and years and years, so it wasn't as if there weren't stories to adapt, right?
So, you want to know what torques me off even more about how often these shows get cut off? Let's look at Scooby freaking Doo... between the various shows featuring him (and not including Laff-A-Lympics, mind you), there's been to date a staggering 324 episodes of various Scooby shows, combined! Oh, I know, that's short of the Simpsons' 500 episodes, but that's not aired primarily with kids as the target audience.
I think it's idiotic that the network and studio execs have come up with such an arbitrary number, don't you?