Yes, some HTC apps were said to be good - though on short inspection I found their UI illogical but eye candy was nice. I've used Motorola Android phones - their blur is detested by many. Their applications were very stable, but with spartan features.
Anyway, most OEMs can make very simple acceptable software, or slightly complex bad software, or complex shit software. The lock-in comes from complex software - parts of which reside in the "cloud" which are insanely complex. Beyond capabilities of most OEMs in their wildest dreams.
Their any hope to compete with the big 4 - Google/Microsoft/Apple/Amazon in the software department is in a next generation Symbian. The half-hearted attempts of Samsung as ShakaUVM mentions don't even begin to address the gap.
The problem for people who don't drink the Google kool-aid is that hardly anyone is working on the AOSP versions of most apps
Google isn't either. More and more, they are replacing the AOSP software with "Google" software. Without publicizing that now they are all closed source, while still reaping publicity benefits of Android's earlier image of open source. Sneaky.
terrible UI and doesn't integrate nicely with the rest of the system. There are a couple of sync adaptors, but Google has increasingly broken the sync APIs
Currently I am using the local calendar adapter for Google calendar, from F-droid. Works well. There is a similar CalDAV adapter too - doesn't it work nicely with owncloud? I was hoping to use it some day.
Anyway, that was my point. Google and the other big 4, really do good UI - much as I hate to expose my data for their inspection.