Going with the majority opinion on
Tusk. Her material there is simply the best she's ever done.
The second choice is more difficult.
Tango and
SYW are easy to eliminate. Clunky lyrics, uninspired vocals, etc. I like a *few* of her songs on SYW, but Lindsey is much stronger to me on that album.
Mirage, of course, offers "Gypsy," which could be the finest recording from the Rumours incarnation. I personally adore "That's Alright," and "Straight Back" is a good song, but I hesitate to rank them among her very best work.
So that leaves
Rumours and the white album. It would be easy to choose
Rumours. "Gold Dust Woman" is magical and "Dreams" is a wonderful pop song. IDWTK is a really fun song, and IMO fits on the album better than "Silver Springs" would have.
I think "Silver Springs" emerged at its right time.
You know, I'll go with the white album. "Landslide" is her most timeless song, and the one she'll be remembered for. "Rhiannon" was the great beginning. And she wrote a beautiful, pure love song in "Crystal."