Sansa Clip+ was very close to audio player perfection as far as I'm concerned. Simple but functional, no frills, had exactly the features it needed, no less and no more, and at a very reasonable price. Rockbox made it better, but even without it was pretty darn good.

I don't recall what happened to mine (lost? broken? gave it to someone? don't recall), but I wish I had bought 20 of them when I could to last the rest of my life.

I had an RCA Lyra RD1021, it was almost the size of a matchbox. I’m still tempted to use it while running instead of a phone.