I just watched it, and after getting only 10 minutes into Superman: Unbound, I did not have high expectations. However, I ended up really, really enjoying it. More than anything, it's a film with consequence and heft, where I felt the impact and cost of death. Barry Allen was the most interesting I've ever found him (I've always been a Wally West guy) and all the characters were filled with purpose. Overall, the top 5 DC Animated films are:
1. Batman: Under the Red Hood
2. Justice League: The Flashpoint Paradox
3. Wonder Woman
4. All-Star Superman
5. Green Lantern: First Flight