Debian and KDE would make a solid experience, but that's not what this user is looking for.
They're not going to know what Debian or KDE are, and they're not going to have the requisite knowledge to know that you're probably recommending Kubuntu.
Kubuntu is a great choice, but since we don't have all the information on the user's needs, it might not be the best choice.
There's some really good recommendations in here, but we can't settle on what to recommend for you without a little more info.
Which one should you pick?
The answer is No (and also yes).
Huh?!
The real answer is not to pick one, but to pick more than one. You can (one at a time) install each of them onto a USB then change your computer's settings to boot up from the USB instead of windows. That way you can try each one to see what you like without installing them on your computer first.
For each one you try, you can check:
Then once you're ready, you can install the one you want to use onto your laptop.