Batman is a must, it is the defining run thus far in the New 52.
Detective Comics is a beautifully drawn and well executed comic, you may want to check it out.
Batgirl is amazing. Black Canary is spinning out of that title, so it too will be good (most likely). I will say the art is a little different than the norm, so you may want to check out the preview before you buy.
Superman has a new writer, no telling if he will be good or not. If you like Superman, I highly suggest Action Comics. It has a solid, well proven writer in Greg Pak.
Speaking of Greg Pak, I suggest you check out Batman/Superman (as you seem to like both characters).
Wonder Woman's new creative team is alright. If I might offer a substitution, I would suggest Superman Wonder Woman.
Robin, Son of Batman looks really good. If you like Robin, then why not try Grayson (who was the original Robin)? He's a James Bond-like spy now. The comic is really solid, I highly recommend it.
Justice League is another title that has been really fun and interesting. There were a few dud issues in the run but all in all it has been great.
Everything in June is considered a jumping on point, including Batman. While I recommend reading all of Snyder's run. All you need to know for June is Batman apparently perished fighting the Joker
I recommend anything Superman, Wonder Woman, Batman, Batgirl, Robin, Grayson, Aquaman and definitely read the previews to see what catches your interest.
From that list, the must have titles are Batgirl and Catwoman. I'm not really a huge fan of Snyder's work on Batman but it still has its good points.
I would also recommend you to try Gotham Academy which is certainly one of the best titles that DC is currently releasing both in terms of writing and art. Black Canary seems to be following that route too with a similar tone as Batgirl (and written by the same writer).