I thought that this was a really tough question, but a very good one!
I had to think on it a few days.
(1)Fleetwood Mac--Live in Passaic 1975. My all-time favorite. It has the Welsh Witch intro, which is neat. She hits all those notes perfectly. She is just so "into it," and I think this version especially highlights that era of Rhiannon. The guitar solo is great. I love the ummmmmmmmmm's before she does "Dreams Unwind~~Love's a State of Mind." I love the yell at the end. Perfection all the way around!
Here are some others I really like, as well. I like each of these for different reasons, but I'll save you guys the blabbing and just list these
:
Stevie Nicks---9/17/94 Hollywood, CA "Welcome to My World;"
Stevie Nicks--"Dreamer" (complication from "White Wing Dove Tour and "Wild Heart Tour);
Fleetwood Mac-Shine Angel from St. Louis 1979 and Oakland 1982; and
Fleetwood Mac---Dancing Alone--(It is a live, Dance era version, but her vocals are really up front on this track.).
If I could pick a favorite studio version, I would have to go with the Single Mix, which is on Fleetwood Mac B-sides and More Disc 1. It is just fabulous!