Since I have been following Inbox Zero for quite a while now, the only email seen in my inbox are unread email. If there is new email when I open Gmail, it is acted upon immediately or_ moved_ to other labels (folders) for later action. So, there is no point of the read-unread status of email in the inbox for me. Also, I do not like to see my inbox showing a unread count or seeing new email in the unread style (bold fonts).
In short, I would like all my incoming email to be marked as read. Since Gmail has no setting to do this, here is how I use a filter to achieve the same: