I'm not sure which one to vote for... not because I can't decide which one is better, but rather which one is worse. I like the music in the Patty Smith version, but I really do not like her singing at all, especially in the last 1/3 of the song.
The Grand Funk version has issues too. It sounds way too psychedelic for my tastes, but worse than that, the bass and drums really drown out the guitar. Very poor recording (IMHO).
I may just abstain. I'll admit, I'm very critical of remakes of this song as it's probably my #1 favorite Stones track of all time.