Batman Beyond is one of the coolest shows ever. The creators built upon the excellent Batman: The Animated Series, expanded the Batman universe, and added some awesome future tech. The writing was solid but what elevated the show from good to great was the art. The clean lines and stylized characters really sold the setting and the stories. The comic book which sprang from the TV show was almost as good and it looked just as pretty.
I like this for a lot of reasons but the main one is that it reminds me of Steranko's Nick Fury covers. Also, the colors are exciting and the composition is great. It does that "catching the eye"' thing that a cover should.
#21 & #22
Both of these grabbed my attention because they've got a bunch of characters who are almost the Justice League. It makes you ask, "Who the hell are these people?". Of course, if you've seen the animated episode this comes from you know that they are, in fact, the Justice Leage of the Batman Beyond era. This was one of the best ideas anyone ever came up with and it involves old-school Batman's "prepared for anything" superpower.
Also, that little, bald Green Lantern dude is just freaky. And anything with Big Barda in it gets extra points from me.
There's not much I can say about this other than, "WOW!" If you don't think this is an awesome cover your soul is dead. I'm totally gonna get this painted on my van.