Sherlock Holmes

I have read some Sherlock Holmes series lately. This series are so famous that I guess I don't need to explain and I know many people love them. In my first impression, however, I couldn't understand why many people love Sherlock Holmes. What I read up to now was "Sign of Four" and "The Speckled Band". These were exactlly easy to read and understand the story, but I thought they were nothing but just usual mystery novels. I should have read in chronological order, but I am not sure whether or not it can be more interesting than when I read in random chronological order.

I hope someone would explain to me what made Sherlock Holmes so attractive.