I was an absolutely massive Adric fan when I was younger, his death was probably the most traumatic thing that happened in my childhood. I can remember weeping for hours after Earthshock, and writing stories on how he could have really been saved by a future Doctor
As an adult I have to say that I find him a tad irritating, but I can still see why my younger self thought he was a hero. He questioned people rather than just accepting what he was told, and he tried to solve problems in a different ways. I just wish that he had learnt more by his mistakes, I think he would be a more popular companion if he had shown more growth during his time in the TARDIS.