I use a Targus laptop backpack, in all honestly it was the only one that I could find that will carry my pseudo desktop computer (17.3" 9lb laptop) and it's served me very well. I pack the laptop, charger, about 3 reams (1500 sheets) of my paperwork, mice, disks, medication, vaping gear, and empty coffee cup (or water bottle) and from what I remember it was pretty inexpensive. I did have to add a cross chest connector though since putting all of that into the backpack makes it weigh a lot, a lot more than is comfortable without having the cross chest connector to keep the two arm straps closer together.
But it's been very rugged and I don't see any signs of wear even though I've been using it extensively for close to 3 years now.