With the power of apps, there are tons of stuff a per son can do besides the typical stuff people already know (and have mentioned in this thread). And the bigger screen/S Pen only makes some of those things easier or more fun.
For example, musicians can compose, record, and mix music with music-production apps (although the options are far more robust on the iOS ecosystem, due to how bad Android's audio latency is). You can record/edit podcasts too.
Writers can write novels with dedicated writer's apps.
Artists can draw and paint with professional art apps. (Most Note users have no idea that the Notes are using professional level pressure sensitivity from Wacom's technology. Samsung doesn't advertise this as a selling point for some reason, when it is in fact a huge deal, considering that the Note is basically like a mini Cintiq).
Serious photographers can use high-end photo-editing apps to do digital darkroom work.
For non-creative people, there are so much you can do too, since today's smartphones are basically smaller computers. You can do things like:
Time/Project management with dedicated apps, for both professional and personal life.
Collect and create recipe for cooking.
Do research on the web whenever and wherever.
Take photos of important stuff and keep them as records with you--official documents, credit card info, car registration, business cards, etc. And there are apps that can protect your data with encryption/password.
My wife and I often just use the phone's camera and snap a shot of an address/phone numbers that's on the TV/computer screen, so we don't have to jot it down or type it out. This is extremely handy when we need to go out and is in a hurry. This method is also extremely useful when we snap photos of broken items we ned to shop replacement solution/parts for. We just go to the store and show the staff the photos, instead of lugging in the item itself.
There are apps that track how much exercise you are getting, and what you've been eating.
There are apps for just about anything--for bar tenders, chemists, doctors, mechanics, programmers--it's all about how smart and resourceful you are as a person. Sure, you can just watch movies and play games and surf the web with your smartphone, but you can do far, far more with it.