It's unfair to compare anything to the season opener (Indelible) because of the subject matter and the wonderful way it was presented but, that episode aside, this is my favorite since Stella (who I still miss) left.
I always enjoyed the earlier episodes which featured two cases. I felt they added something to the show and were unique compared to other procedurals which focus on one case per show. This show had not only two stories which confusing causes of death, but also mysterious happenings with Sid and Mac's friendship with his late partner's sister, which was a heartwarming way to conclude the episode.
I think what I love most about CSI: NY are the relationships and how the team genuinely care about each other. Yes, team dynamics and well written plot lines are vital to any show, but I enjoy these more. Whether it's Jo reminding Sid that lawyers and accountants are not the same as friends, Danny and Lindsay teasing each other in the park, Mac looking out for Christine and the success of her business, Jo playing the piano or any number of those 'milk of human kindness' moments that permeate the series, they add up to remind us of the innate goodness of most people and that's nice to see as a counterbalance to what we see far too much of on the news.