Okay these are 'obscure' in the fact that not a lot of people know of these particular performances or remixes/covers.
Bluegrass instrumental cover of "Taylor" by Jack Johnson that is a very beautiful version. If I ever got married, I'd probably want this to be the song playing. https://www.youtube.com/watch?v=Q23KUT6W8HA
Another amazingly beautiful song: Roads Must Roll https://www.youtube.com/watch?v=U7DYYQ4q4Go
This remix of "Sound of Silence" used in this emotionally powerful video for hearing impaired that I stumbled into over 10 years ago. https://www.youtube.com/watch?v=Bo7fAjfp098
This guitar instrumental cover of Billie Jean by Michael Jackson that this amazing kid does https://www.youtube.com/watch?v=CgVqX0a49HM
Throwing Fire by Ronald Jenkees You wanna get pumped listening to a guy rock out on a keyboard? This dude has some amazing jams. (I also recommend Disorganized Fun, Stay Crunchy, Guitar Sound, etc) https://www.youtube.com/watch?v=0O2aH4XLbto
Destiny by Zero 7 before they were really big, and before Sia blew up as a pop artist. This particular version is really tight. https://www.youtube.com/watch?v=Xxx_MwcfbEs
Hip Hop violin by Paul Dateh and Inka One. Its old, the video quality is awful, but the music is. Amazing. https://www.youtube.com/watch?v=36Xt-XeWnHM
I'll probably add some more as I think of them because I love music.
Lebanese Blonde by Thievery Corporation Okay this is a well known song because it was used in a popular movie called Garden State, but not many people know the band outside of 'oh yeah that cool song from Garden State!' But this is such a talented band, if you can see a live show of theirs, do it. One of the best concerts I've ever been to in my life. https://www.youtube.com/watch?v=1t7W6NtTKAw
Cover of No Diggity by The Regulars https://www.youtube.com/watch?v=1be7E48Yhas
Broken in All the Right Places by I Am Jen A woman I found on YouTube over 10 years ago https://www.youtube.com/watch?v=832YvQHzFqg
1976 by RJD2 https://www.youtube.com/watch?v=HC-FGtZrPkU
Staying' Alive instrumental cover by Luca Stricagnoli https://www.youtube.com/watch?v=buH9qCgK_Qk