Grey's Anatomy is my wife's favorite show so I end up watching most weeks with her. It's mostly alright. The early seasons were quite good then around season 4-5 it went quite downhill for a few years. It bounced back though and got a lot better. Recently it seems to have gone downhill again a bit but still better than those few terrible years in the middle.
How to Get Away With Murder had a really good first season. Season 2 stunk. Season 3 so far has been better though not as good as the first season. I'm a few weeks behind as I haven't watched since it came back. Its a really good binge show so I usually let it build up a few weeks and then watch them in a row.
As for Scandal, only seen a few bits and pieces here and there. Seems fine. Big fan of Kerry Washington but I wish she'd go back to interesting film work.