Adams® Vehicle Mileage And Expense Book, 8 1/2" x 5 3/10"

Pros: convenient, easy to use, lies flat, has all information you need for keeping track, pockets in the back for receipts

As a tax preparer, I know how important it is to keep a mileage log yet many people do not do it because it is such a hassle. This log is perfect, it is sturdy, has many spaces and asks for the exact information you need to have for the IRS to accept it in an audit. It is also easy to read and because of the spiral binding, it can lay flat on the seat next to you making it more convenient to keep track of your mileage. It even has pockets in the back of the log for your fuel, service, etc. receipts. It can't get better than that.