This one caught my eye the first moment I saw it. The other covers are great but this ones seems to truly stand out...... My reasons are as follows:

1. Your name stands out without being bigger than the title.
2. Clean lines with each section of the cover having a specific use.
3. Insptie of the angular lines the text is primarily on one side and the logos are on the other. This helps them both stand out separately (text and logo on top of each other sometimes mixes them and makes them loose their individuality)
4. Looks professional and states the purpose of the book clearly without being 'boring'