If you have a 17 inch laptop, you need to look at good 17” laptop bags if you are going to carry it around with you. Why do I emphasize the quality of the bag here? The reason is simple and may be obvious to you, but I’ll say it here. A 17 inch laptop will be heavy and most likely be expensive. If you have a heavy laptop, you’ll need a bag with lots of padding inside. The padding can make a big difference if you drop the bag.
Most laptop bag manufacturers have drop specifications. They basically guarantee that a drop from x number of feet will not damage the laptop. I would recommend a 4 foot guarantee at a minimum. This will assure you that the bag has adequate protection for your computer in the event of an unfortunate incident. Imagine dropping a $2,000 computer and shattering the lcd screen. This is not something you want to happen and you should take steps to protect your investment. Even if the computer is not worth much, your data certainly is. If you are a computer professional, you already know that when looking for 17” laptop bags, protection is a top consideration.
If you travel frequently, I would suggest a bag with rolling hardware or a shoulder strap. Shoulder straps are great for relieving the stress from your hand. If you routinely carry lots of things in addition to your computer, consider getting a bag with wheels. If you get a bag from a reputable manufacturer, there will be other thoughtful touches. There should be dedicated places to put optical discs, peripherals such as cables and external usb devices like usb mice or usb memory sticks. All these little refinements can make life much easier and you should look at everything when selecting your computer bag.
You may have a smaller computer than the 17” laptop bags are designed for. Maybe your computer has a 15” screen. It is OK to go larger, getting a smaller bag is the problem. Always get a bag that fits your largest laptop and one that has room for expansion. You never know what the future will bring.