Samsung TV plus app, lots of free channels. Not for me but app looks good with lots of free content
Google feed option on the left of the home screen is the biggest addition for me. Absolutely love my Google feed and used to switch to Nova on Samsung phones on order to get Google feed. But with One UI launcher giving this option it feels nice to stick to phone's original launcher with Google feed.
And as others have mentioned, best fingerprint till date on recent Samsung phones. This one is very fast and accurate compared to the previous gen phones.