A great straightforward rocking cover:https://www.youtube.com/watch?v=ajCqrg0jucw
(By MandoPony, who does some of the best covers on the Net of songs from the show)
An also rocking garage version that wanders just a little bit off of the normal song timing:
This one that's way off the normal song, with lots of rock references including a Beatles scream which is what wins me over:https://www.youtube.com/watch?v=AubDY7SkJhU
(The video that introduced me to all the MLP ROCK! videos by Claire Anne Carr.)
This delightful acoustic version of the song by MandoPony:
And many more:https://www.youtube.com/results?search_query=babs+seed+cover
The upshot is that the chords are pretty easy, here they are:
http://tabs.ultimate-guitar.com/m/misc_unsigned_bands/cmc_-_babs_seed_crd.htm
More amazing Babs Seed covers and where they lead:
Here is something utterly incredible:
That in turn was based on something from the utterly incredible PhillyPu, who produces all kinds of things MLP:
Including this clubified Pinkie Pie remix that I might not stop listening to ever:
Then that leads to this pretty nice setting of Pinkie Pie video clips to a preexisting club song:https://www.youtube.com/watch?v=z6ePliP9M4c
Which in turn leads to hundreds of similar "PMVs" of just this one song, but also other music too.
Babs Seed 8 bit on a Gameboy, pretty impressive:https://www.youtube.com/watch?v=14yim_M1CcU
Many other 8 bit covers in the suggestions.