Linux Mint is my go-to operating system for anyone just now switching to Linux.
The Mint team has created a desktop environment called Cinnamon that resembles a traditional windows layout, yet it contains modern features including account and calendar syncing. While the default desktop is Cinnamon, the official options also include XFCE and Mate desktops. The package core is Ubuntu, but the team also releases Linux Mint Debian Edition (LMDE) based on Debian that is a backup in case Ubuntu becomes a problem.
The Mint team focuses on hardware compatibility, so it uses an older Kernel to support a wider range of hardware, though you can use the built in Kernel manager to install newer versions. Also, if NVIDIA is a problem, the installation media also includes a build that installs the proprietary video drivers as well. Overall, Linux Mint works on the broadest available hardware with minimal issues.
The install includes many system tools to feel like a complete OS including disk utilities, USB drive writers, a character map, and basic tools to do all the primary tasks you would expect your computer to do including web browsing (Firefox), email (Thunderbird), image manipulation (Drawing), image important and management (Pix). The desktop UI on all three desktop environments is familiar to the average computer user making it a simple choice for someone to jump right into a new computer.