To be honest, it will be hard to find both superb sound quality with any small (especially low-cost) speakers, and what sounds best to you, is strictly a personal matter. As such, what would sound best to me is no way a guarantee it would for you.
Audio quality comes down to, at least, three things:
- The source. Lossless (uncompressed) audio provides the highest sound quality vs. compressed audio.
- The ability to stream that source. Apple's AirPlay 2 supports streaming lossless audio. On the other hand, Bluetooth cannot.
- Your ability to hear it. As you can imagine, as we age, our ability to hear the full spectrum (typically 20 - 20,000 Hz) of frequencies is significantly reduced, especially on the higher end of that spectrum.
With that said, If you prioritize audio fidelity and video sync over portability and are in the Apple ecosystem, the HomePod is the clear winner — especially for a mixed music and movie experience. If you need on-the-go use with solid sound, and you’re okay sacrificing a bit of that immersive quality, then the Bose SoundLink Flex is the most versatile. Personally, I'd skip the Beats Pill unless you already have one or find it super cheap — it’s outclassed now in both audio performance and features.
Regardless, of which you go with, be sure to understand the store's return policy in case it doesn't meet your needs. With Apple, you typically have 14 days to return items for a full refund. For Bose, that would be 90 days.