Surely Linux Mint is one of the best out there for desktop PC if not the best.
I'm not sure if I have to mention what follows here, but i give it a try.
1. One of the major things that I believe MINT should have as it persuade user friendliness in all aspects
is to add the back and forward mouse button ability to Nautilus, like Firefox already has it.
There are some simple scripts out there that are very small in size.
2. Conky , Conky, Conky.... It is just amazing what it can do... Simple, scripts can
make Mint to look Sophisticated, Comfortable , Powerful and in charge.
A simple RSS + some System Info ( Like Damn Small Linux ).
I think, the small well thought differentiations are what make Linux Mint so sexy,
and not BLAH like UBUNTU ( No offense to UBUNTU lovers, UBUNTU is great....)