With the rich history of our favourite band, picking the best song is really hard so I think best broken down into era 1 & 2:
Green/Spencer/Kirwan: Closing My Eyes and Oh Well Pt 1 and 2
Spencer/Kirwan/McVie: Jewel Eyed Judy and Station Man
Welch/Kirwan/McVie: Woman of a Thousand Years and Future Games
Welch/McVie/Weston: Miles Away (opening riff is one of the best mac moments) and Believe Me
McVie/Buckingham/Nicks: Over and Over and The Chain (honourable mention to early live Rhiannons)
McVie/Nicks/Burnette/Vito: Behind the Mask and As Long as You Follow
McVie/Burnette/Mason/Bramlett: Sooner or Later and Dreaming the Dream
Nicks/Buckingham: Come and Thrown Down (hope to add one of the new songs here, fingers crossed
)