Entry 6 - This looks great - We like the use of blue and grey, and the circle graphic with the asymmetcial "H" is a little different in a very good way. We also appreciate that you created depth with gradients.
Entry 5 - This also looks great; Entry 6 edges this one out by just a bit.
Entry 4 - We're really looking for something with a graphic element, like Entries 5 and 6, and not just our name.