What about that Twisted Adventures of Felix the Cat cartoon in the 90s?
That wasn't really a hit at the time, and it has a bit of an online fanbase now. We're not talking a Simpsons level of memes, but it's decent. So I'd say that's something that's endure to a fairly minor extent, but more than I'd perhaps expect.
Honestly, it’s not very easy to answer this question because I find it hard to measure in some way a property at the height of its popularity and its current status as suggested to be a zenith.
Yeah, it can be difficult. Other threads along these lines have gotten a little contentious because it's hard to define how big something was in the past, and how forgotten it is now. For me films like Pocahontas, Anastasia and Bolt seem about as "remembered" as I'd expect; they weren't The Lion King or Shrek back then, and they aren't now.
I agree with A Bug's Life though, not that it's completely forgotten, or more forgotten than the films I mentioned, but more forgotten than you'd think if you can remember its release. For whatever reason Pixar and Disney quickly decided that was the black sheep of their family, and the public seemed to agree.
Also a lot of us here probably grew up or otherwise got used to a time when TV and especially films had a long life that we assumed was normal, but will probably turn out to be a relative blip. Between VHS, Cable, Satellite, Syndication, DVD and more, even a Critical/Box Office flop could retain a degree of cultural relevancy for a decade, maybe more. Before then, a choice few films were remembered and kept in circulation, in the streaming age works will likely be buried under the miasma of (mostly new) content. This is particularly the case for cartoons, which would often be rerun constantly to keep family audiences entertained, e.g. in 1997 George of the Jungle was familiar enough to be the basis for a big budget film, even though the cartoon had only lasted for 17 episodes 30 years previously.