My thoughts on ongoing series:
I love Legacy. It takes place roughly 137 years after ANH and it features a whole new Skywalker, a dude named Cade. Initially the story feels like a retread of the PT/OT, but Cade is far more of a complex, anti-hero than either Anakin or Luke. He's actually my least favorite character in the book, but the writers and artists create such an interesting milieu that I keep coming back.
Knights of the Old Republic. I've collected this sporadically, however it often gets critical raves. The artwork is up-and-down, but for the most part I think the stories and characters are engaging enough. Unfortunately this book is about to wrap up at Issue 50, I believe it has about two issues to go. I would definitely check out the trade paperbacks at a book store to see if its something you like.
Clone Wars: I think this is going to go quarterly. Right now I think its monthly. The style is similar to the Clone Wars cartoon, though the artwork is so-so at times. The stories take place during the current run of the show, but what I like about it is that is just doesn't focus on Anakin and Ashoka all the time, though they are major parts of the book.
Invasion: This one I don't care for as much. It takes place during the New Jedi Order novels, with the Yuuzhan Vong invasion. If I were you, I would just read those novels, if you can find them.
Dark Times: The first volume The Path To Nowhere was great. This is perhaps the darkest of the current comics. It takes place shortly after ROTS.
