Homeland was great. Its funny cause the start of each season you would be like "is this show still good?" and then by the end of the season think it was great. Some very good acting throughout (Claire Danes, Mandy Patinkin, F Murray Abraham, Damien Lewis)

Dexter is great in parts. It does get less so as it goes on; you have minor one note characters that start in the background come to the forefront and get more screen time, but not really any better. The main line arcs are pretty good each season.

Newsroom is great if you like Aaron Sorkin's style; fast pace, idealist dialog. If you have watched his stuff and didn't care for ti, it is not for you.

Boardwalk Empire I enjoyed a lot. Semi historical crime-mob drama set in the 1920s. The last season went off the rails as they found out late it was gonna be the end and to wrap things up.

Ray Donovan was ok. What you see at the start is mostly how each season plays out. Nothing great, or extremely interesting, but never really bad either.

I'd recommend them in the order I have listed. Only bump up The Newsroom if you really like Sorkin TV/Movies, or bump to the bottom if you don't.