Superman's pretty awesome, right? My favorite thing about Action Comics is the title. Action! That's a great name! This is a comic that has spanned every age anyone has come up with a name for, so far. Therefore, there's a lot to make fun of. There are some wacky golden and silver-age stories back in there.
There are also some awesome covers. Here are a few:
With the possible exception of Fantastic Four #1 this is the most homaged/parodied cover in the history of paper. It's also awesome. Look at that guy! He's picking up a freaking car! What the hell? It's iconic because it works, mate!
Here's a non-Superman cover but look at it! This is why they call the thing Action Comics! Excellent composition and I want to know what's going on there. Also, nice suit, guy.
I like this one for the wacky use of color. It's eye-catching and I've gotta find out why Superman is punching a spinning shaft of light.
This one sort of falls into that realm of "Weird Things Happen To Superman And Are Then Reversed" but the cover is creepy as hell. I mean, look at those robo-Supermen in the closet. That's messed up.