Which characters come to mind when someone asks you who is a well written character?
One character that stands out in my mind is Professor Severus Snape from the Harry Potter series. Throughout the entire series, you constantly question yourself about whose side he’s on and that it isn’t revealed until the very end of the final book. While you can clearly see the motives of the other characters in that series, you don’t see his until the very end when all is revealed. I couldn’t even begin to guess until I finished the final book.
Mordecai Tremaine is another well written character. He is a retired tobacconist and an amateur sleuth that helps find out who the murderer is in each book written by Francis Duncan. Each book is a classic “who done it” mystery. If you are a fan of Agatha Christie, these books may be of interest you.