By the way
That is Gloria Steinem in the end panel
One of her first reporting job was being a Playboy Bunny.
She was also responsible for Wonder Woman getting her powers back after DC comics had her lose them
Wonder Woman.was on.the cover of the first issue of Ms Magazine which Gloris created.
Definitely check out Kingdom Come and Justice Society of America: Thy Kingdom Come! Those are my personal, all time favorite comic book tales. Superman: Secret Origin, Identity Crisis, and Batman: The Long Halloween would round out my TOP 5 favorite tales. And as for entire runs, Jeph Loeb’s Superman/Batman is ABSOLUTE greatness, Geoff Johns’ Green Lantern is one of the BEST superhero stories ever, Levitz’s Legion of Superheroes is ESSENTIAL, and Palmiotti and Conner’s Harley Quinn is a MUST read. There are SO MANY more amazing stories, but I guarantee these will not disappoint!! Happy reading!! 
My advice is to take what you’ve read (even the marvel stuff) and pay attention to the writers. Then I would try to follow the writers. I know that doesn’t really narrow it down for you. But I feel whenever a writer starts a run is a good jumping in point and it might be a safe bet for something you might enjoy. But also seeing what everyone’s posted so far those are all good jumping in points.
One thing you have to determine with “jumping in points” is where you want to jump in. You may want to sample a few stories from each era to get a sense for how you feel about various periods in DC history. I’ll give you a sampling of various “jumping in points” (before the obvious one, the New 52) for Batman available on DC Universe.
A. Golden Age (1939-1951)
Detective Comics #27 (1939)
Batman’s first appearance. Obvious choice? Maybe, but the character is still in the process of being defined.
Batman #1 (1940)
Joker’s and Catwoman’s first appearances. The beginning of the classic rogues gallery and the final instance of Batman using a gun to kill the villains.
B. Silver Age (1956-1969)
Detective Comics #298 (1961)
Clayface II’s first appearance. The wacky, absurd early Silver Age adventures continue through issue #326.
Batman #164 (1964)
First appearance of the yellow Batman logo. The stories begin resembling the Golden Age again. The same shift occurs in Detective Comics #327.
C. Bronze Age (1970-1986)
Detective Comics #393 & Batman #217 (1969)
The stories that begin the status quo change of 1970, where Robin goes to college and Batman lives in a penthouse.
Detective Comics #469 (1977)
Rupert Thorne’s first appearance. The arc that begins here sets in motion the events of the early-to-mid 1980s Batman stories.
D. Dark Age (1987-2000)
Batman #401 & Detective Comics #568 (1986)
The first issues directly tied to post-Crisis continuity. They are quickly followed by new writers’ runs and the Year One/Year Two stories.
Batman #0 and Detective Comics #0 (1994)
The first issues following Zero Hour. Dick Grayson briefly fills in as Batman before Bruce returns with a darker costume.
E. Modern Age (2000-2011)
Detective Comics #742 & Batman #575 (2000)
The first stories set in the rebuilt Gotham after No Man’s Land. Crispus Allen’s first appearance and a shift toward a focus on the Gotham police.
Detective Comics #817 & Batman #651 (2006)
The first stories set after Infinite Crisis. Batman quickly brings order to Gotham, but a major shakeup comes a few issues in with the arrival of Damian Wayne.
The Blackest Night series has many of the DC characters. It is one of my favorites. It really highlights characters strengths and weaknesses. This event included Wonder Woman, Teen Titans, mainly the Green Lanterns and other lantern corps, most of the Justice League. It is an epic event with great artwork. I don’t know how many times I’ve reread it.
It was one of the series that had me branch out and explore more characters.