I felt like watching a cartoon since I've been mainlining the first season of Game of Thrones. Justice League: Doom hit the spot since I like superhero cartoons and WB usually does a pretty good job. The animation was just ok, but they had the usual voice actors so it didn't really feel like a low budget affair.
The plot was a standard one and there were plenty of instances of bad movie physics, but, overall, I found this movie entertaining and I recommend it to comic book fans. I think it presupposes more character knowledge than a casual fan would have and it's a little rugged for those under 12.