The 747 has two things going for it interior-wise that distinguishes it from all other aircraft out there, and both are somewhat special so they can make a trip memorable on their own:
First, when you sit at the very front on the lower deck, you can look out the windows in a far wider angle than on any other commercial aircraft because of the way the cabin walls curve in and there's no cockpit in front. To enjoy a view like this you'd need to sit in the cockpit on any other airliner, something that hasn't been possible for over two decades now. Flying towards aurora borealis on a 747 seated in row1 was an experience I'll never forget and I'm grateful to have had the opportunity.
Second, the upper deck - being much smaller and way more intimate than the full-length one on the A380 - has a very private feeling to it depending on the seating installed by the airline. I've flown a lot on BA 747s with their suite-type seats, and I'm definitely not the only one who describes this experience as a poor man's private jet.

The A380 is "better" in every metric regarding passenger comfort experience, and that is what matters - it has lower NVH levels (=it's quieter), motions are damped better especially on the upper deck , it has a wider cabin (=more space), a lower cabin altitude with higher humidity as well etc. And that's no wonder because it's a 2000s clean-sheet design whereas the 747-8 is the final update of a design that's been first on drawing boards in the mid-.1960s.