probably the first or the last...
All are grand
All are good, but I love the first and the second in particular.
The first one looks mysterious. I like that one the best.
I like the violin one - just because I'm a violinist. ;)
The last one looks kind of spooky if you ask me.
The first one makes me think "Sherlock Holmes" instantly. I like the second to last most, but I doubt many would think of him when they saw it.