Linux holds a special place in my heart, and I prefer to use Linux over macOS and Windows as my desktop OS. Likewise, many of the laptop models featured on this site hold a special place in my heart. Laptops like the ThinkPad T480 are iconic workhorses with a cult-like following. I think refurbished business-grade laptops are one of the most overlooked deals in computing. Businesses buy thousands of these laptops every year and recycle them all two or three years later when they upgrade their fleet, flooding the market with supply. The laptop models I choose to feature on this site have exceptional build quality and upgradability, and great Linux support. Whether you're looking for a cheap way to test the waters with desktop Linux, or you want a fully spec'ed mobile workstation, a refurbished business-grade laptop might be exactly what you're looking for!
The 7000 line of Latitudes is Dell's high-end ultrabook line. These are excellent laptops that are lightweight, easily repairable, and run Linux well. Dell even offers manufacturer support for Ubuntu Linux in this line, where you can buy a new Dell Latitude with Linux from Dell, so you know there's great support from the manufacturer for things like drivers.
The ThinkPad is perhaps one of the most iconic lines of laptop computers ever made, and is a favorite among many linux users. They're also known for their quality and repairability. Some models (like the T480) allow for both an internal and external battery pack, with up to a combined 96Whr battery capacity.