This show has the capacity to shake you from inside. High on emotions and leaves out a great message to just...just talk to people around you. Don't ever ignore them. We really don't know what happened/ is happening in somebody's life.The show explicitly touches upon those issues through emotional and tragic story of Hannah Baker.
The first season makes you empathize with Hannah and makes feel characters, or in some way makes you feel too, the guilt of not helping Hannah and letting her down. Clay's guilt (in particular) makes you question how things for Hannah would have been different if they both have been open to each other and had confessed what they felt for each other. This season leaves you with a sense of guilt and awakening of your own surrounding.
The second season further unfolds all the character's life. And upholds the values of friendship and family. The ending appears as if its a vicious circle to which there is no way out. A situation arises where the major characters thinking that now things are over and they all can actually move on and suddenly another outburst happens which puts them in another similar situation where they will be tested of what they learnt from Hannah Baker's story.
In my opinion, once in a while, have a look at this show. It will be an emotional and exhausting sometimes but will provide you insight into some of serious issues which we take for granted.