If you like DC history and comics, it's a pretty fun time. So many cameos from Lucifer to Smallville to birds of prey to flash 1990 to batman and robin to Michael Keaton batman to Kevin freaking Conroy as batman. And he says lines from famous batman movies as well. And just a whole lot of Easter eggs. If you wanted a touching ending to flash 1990, it's there. Plus Oliver becomes the freaking spectre, harbinger betrays monitor like in the comics and the cliffhanger is the destruction of the entire multiverse with a few select paragons trapped outside time and space. Plus Brandon Routh superman is amazing and lex Luthor is a really fun villain with a little twist at the end. If you're a comics need and DC need, even of you haven't watched the shows, watch just this. It's self contained mostly and really worth it.
Well... I guess I have no choice. All of that sounds awesome!