It's not easy to nail down because of the episodic nature of the show. It's literally a new case every episode, so that means a new set of guest stars every episode. So you build a sense of familiarity around the constants which are the cops and lawyers. They start off rough & then you get to know each character as the episodes go on, so as each case changes, it affects each character differently.
I can say that for me personally, everything after Season 12 is a drop in quality because you lose the heart of the starring duo (Elliott Stabler) & they never really manage to fill that void despite a rotation of new cast members. Also, because you're dealing with everything from rape, kidnapping, murder, false reports, sex trafficking, etc. some episodes hit harder than others.
Once they get rid of the first 2 detectives in the 1st Season, they really don't stop rolling until Season 13. Deal with those early rougher episodes & you're set to binge for the foreseeable future.