Board Thread:DC Universe Discussion/@comment-1038387-20121001081404/@comment-1038387-20121009141149

Nightwing had a pretty long ongoing series, I haven't read much of it to know it's all good. If you can find it, Nightwing: Year One (issues #101-106). For the rest, I liked Brothers in Blood (#118-122), which has him facing off against Jason Todd (though I found the ending disappointing). As for new 52 Nightwing, issue #0 should still be in stores.

For the rest, Nightwing pops up in Batman's titles. Battle for the Cowl features his transition to Batman. Gotham Underground has him undercover in the criminal element during a power shift. I also like the Nightwing/Huntress miniseries, but it's more because of Huntress than Nightwing. And I don't think it's collected in trade paperback.