I've been doing "Older Laptop Rescues" on 3-4 year-old laptops their owners are ready to chuck because they're "so darn slow"... those owners don't realise there's nothing wrong with the hardware, it's the OS.
So, I clean that OS as best I can, defrag and shrink down the Win partition which typically leaves a good-sized area to install Mint with the Cinnamon DE. I do check back with these users to make sure they're happy with this: uniformly elated!
I chose Cinnamon because for Windows users, it most closely resembles what they're already used to. To me, honouring workflow and respecting people's hard-earned knowledge of computing is crucial for getting them to accept a new computing environment.
As we say here in Oz: "new isn't always better"... there has to be visible, appreciable benefits to making a change. So, I make sure not just that these new GNULinux converts are initially happy, but stay happy!