>>1549525For anime, The stuff that would come to mind as the best examples already got mentioned.
Some scenes in stuff like "Hellsing" and "Cyberpunk Edgerunners" were Goofy, but the overall tone of the series was constant. So that might not fit.
Death Note has scenes that people meme on (like the potato chip), but it does have a clear tone for most of the series. It's not as whiplashy as code geass gets at times.
I don't know if those scenes are intentionally silly, or just trying to be serious so hard they become silly.
For Manga, you have Stuff like Drama Queen. It has tonal whiplash at times, but it's not really different genres.
If webcomics are fine, then stuff like EnnuiGo or Lookism comes to mind. Both of them are totally different comics and use the "Genre clash" in very different ways.
Those are the 2 best examples I have at the moment.