Apple

I think the iPhone by itself in a vacuum is a rather boring, if high quality device that gets out of the way and gets the basics just "right enough" to not be annoying. For me it's probably mostly the ecosystem. I don't think people understand how nice it is until they get to experience it. Being a software engineer myself, I'm often amazed by how well everything integrates and works together.

• Being able to take a FaceTime call on the Mac or iPad and just transferring it to the iPhone and taking it with you
• being able to take regular phone calls on any device, not just iPhone
• using the iPhone as webcam via WiFi
• opening a tab in Safari on one device and continue reading on the other one
• AirPods seamlessly switching audio sources
• AirDrop (and now NameDrop, too)
• being able to share audio with other AirPod users
• bringing the iPhone close to a HomePod to transfer the currently playing thing, then taking it with you when leaving
• being able to search AirTags
• AirPlay (screen mirror) to big screen
• MagSafe is pretty nice, too, especially with that new Standby feature

I know it's not just iPhone, but Apple has not really been about the iPhone, or Mac or whatever singular device for a long time anyways. I don't think any other company does anything that even remotely compares to Apple's package. Sure, device X from manufacturer Y might take nicer photos when it's raining at night and it's 15°F, and device A from manufacturer B might have a higher res or a higher frame rate display, but iPhone just does all of these basics just right enough plus all the other things I mentioned that it's not even a competition in my mind. Plus, no bloatware (I don't consider Garage Band or Safari bloat, YMMV) or duplicate apps for the same functionality out of the box.