One of them is Rock & Rule. I encourage everyone who's into cult films/animation to see it for themselves if possible, and try to seek out the Canadian version even though it's rare.
Short summary: This movie almost bankrupted Nelvana animation studios, who spent $8 million on it for it to make about $33k in 1983. The colossal flop was mostly due to the distributor MGM/UA not knowing how to market an adult-oriented animated feature and recasting/redubbing/editing the fuck out of the US release version.
To compound on the matter, the original print of the Canadian version was lost in either a fire or a flood, sources are mixed on what happened, and the remaining version is long out of print. A lone VHS copy of the Canadian version was digitized and released on DVD by Unearthed Films in 2005.
Due to the films still being officially out of print (and one version destroyed), physical copies are rare and expensive (physical Blu Ray was going for $400+ on eBay last I checked). And you're likely only going to find the heavily edited US version unless you specifically search for the 2 disc DVD set. The Canadian unedited version is non-existent online, and neither version is available to stream. The US version is on YouTube though.
Overall - great movie, great music, fantastic animation. Very 80s. It's a 10/10 to me.