Which may be its curse really.
There will never truly be a single "Android experience" as long as the cell phone makers and the carriers get to control how it works. The best you can get is like was said, find one that doesn't pile a clunky new UI or something on top of it. And hopefully one that also doesn't load it up with a lot of carrier apps. I remember my last Android. They filled up my free on-device storage with a bunch of shitty no-name social apps in the hopes I would use them. I never did. And I couldn't remove them. (Don't even think about suggesting to root the phone. I looked it up. Not only were all the utilities broken links but the steps were horrible. I don't even like Jailbreaking my iPhone and that's a 1-click process these days.) And because of how Android worked at the time, I couldn't have more than a handful of apps on my phone at any one time because most of the apps from the Play store required installing directly on the phone. 90% of them wouldn't work on an SD card. It was really a bad experience for me and made me miss, and usually opt to just use my iPod touch when I wanted to actually do something. It basically became a texting machine with occasional calling and very slow internet when I didn't feel like connecting my iPod to WiFi. Sorry, this is just a rant about my experience and I know it's not a typical Android experience. Needless to say of course, it wasn't a flagship Android and you get what you pay for. But it was still my first smartphone.
This thread isn't for this though. So let's not start an OS war 2 days before New iPhone Day. Hehehe.