As a (minor) film buff, I almost invariably prefer originals. But when it comes to audio, I have found more than a few covers that I prefer to the originals. So, to kick things off, and with all due respect to Boz Scaggs, I absolutely LOVE this live Incognito version of Lowdown:
https://www.youtube.com/watch?v=dH%E2%80%A6 What's on the top of your lists?