I’ve been using Notational Velocity for note-taking on my Mac for a while now, and can highly recommend it. It’s a wonderfully minimalistic interface, and “just works” for text. I used to use Evernote, but found that I don’t really need all of the features and multiple media types - NV feels like the right fit.
Notational Velocity syncs with SimpleNote, but until recently, I hadn’t seen a decent way to access my NV notes from my Android phone. A couple of months ago however, Notational Acceleration appeared on the scene. It syncs NV notes through SimpleNote. It’s not quite feature-complete yet, but for basic syncing, reading, and writing of notes, it has the same minimalistic feel as Notational Velocity, and “just works”. I highly recommend it.