Where do I start with Batman comics?

[Ticklefist]

Also, not to derail the thread, I've almost finished reading the Knightfall stuff and a friend of mine has recommended the War Games arc. Any good?

I'm afraid I haven't read War Games. It's pretty large, and I've never had much of an interest in Black Mask, who I think is the primary villain in that arc.

I would advise anyone to stay away from War Games. I failed to heed these same warnings and bought all 3 volumes as well as the prequel volume. Here's my take on it: If you stay away from one Batman story/crossover, make it War Games. Everyone was out of character and the story was completely unremarkable. It was nothing but a showcase to kill a character that came back a couple years later to become Batgirl and is now currently lost again in the New 52 shuffle. Absolutely pointless story. Nobody had their heart into it other than Dan Didio. Everyone else just did what they were told and wrote on autopilot. War Games serves as a reminder of just how utterly pointless a comicbook can be.

 

[PlatinumWarlock]

Most of the above suggestions are fantastic ones, though I'd like to throw in an oft-neglected storyline that gets overlooked, simply because it's hard to find:
"Batman: The Doom That Came to Gotham"

It's a re-envisioning of Batman through the Lovecraft mythos, written and illustrated by Mike Mignola (of Hellboy and BPRD fame). It's a really stellar storyline in three parts with some neat takes on the classic Batman rogues gallery.

 

[The Hero Killer]

I personally would start with the first issues of the New 52 series seeing as it essentially rebooted most franchises. Then I would just download the popular one off stories for added history ex. The Killing Joke, Long Halloween, Knightfall...etc. Most of them are altogether in one book now.