In the last year, we've seen a lot of great Android phones - like the Galaxy S III, Note II, One X, RAZR M, or the upcoming Xperia Z. There's little doubt that with every major handset release, we're seeing Android phone manufacturers up their collective 'game.' But way back when (you know, a couple years ago), the fact that Android phones generally weren't always good was a big draw to a Nexus handset for me personally.
I purchased a Nexus One a few months after it was released, and was generally very happy with it. After installing CyanogenMod (which, frankly, was necessary to maximize performance and features back in 2010), that phone stuck with me until late 2011, when I bought a Motorola DROID BIONIC.