Wanna burn a few hours? Then read this What are your definitive cover versions? by Alan McGee (founder of Creation Records (Oasis etc)), and then in a separate Tab on your browser, check out some of the recommended songs from the 300+ comments, on YouTube. Hours of fun and nostalgia.
My favourite one from the comments, bizarrely is Candi Staton singing Stand By Your Man, with an amazing bass hook.
The thing about cover versions is you may know the original song, so it gives you a chance to compare with the original and hear how the song is constructed (or deconstructed!).
So what are my favourite covers? Mmmm, need to think. Off the top of my head….
La Vie en Rose – Grace Jones
Perfect Day – Various (with Lou Reed)
Over the Rainbow – Eva Cassidy
My Way – Sid Vicious
Stand by Me – John Lennon
Hi Ho Silver Lining - Slade