SANDMAN. It's beautiful and literary and actually the reason I got into comics.
Usually it's best to go by authors, and you can't really go wrong with Neil Gaiman, Alan Moore, Greg Rucka, Warren Ellis, Will Eisner, or Gail Simone. Ignore anything even remotely associated with Rob Liefeld, as he managed to ruin some of the greatest comics writers out there.
I second the Blue Beetle and Birds of Prey recs, and would also like to add on Harley Quinn, Lucifer, and 52.
If you want indie comics and graphic novels, that's a whole nother post.