There are quite a couple of shows that I was really waiting for. Some of these are:
Law & Order: Special Victims Unit
American Horror Story: Roanoke
NCIS: New Orleans
How to Get Away with Murder
I already watched Lucifer. I made a review article about the show in Serpentimes. The second season premiere did not disappoint! I really recommend this show to everyone!
I was saddened to see that one of show's regulars dropped out of season three of NCIS: New Orleans. I do not like the replacement so much, but I hope she'll grow into her rule. She has some big shoes to fill.
South Park was amazing as usual!
This season's of AHS has an unusual storytelling. It'll take me an episode or two to get used to it, but I really like it so far.
As for others. Some I haven't watched yet (SVU) or can't (HTGAWM - Need to catch up on season 2 first), but I think they'll be amazing.