it's not really a line but in Black Peter by the Grateful Dead, right after the hook where he sings(is it Jerry Garcia singing?) 'See here how everything...' 'come around' and then he moans and the harmonica comes in in Eb minor. That's really groovy, man. Like harmonicas are alright but it sounded fucking amazing in that song.
Also there's Pink Floyd's Shine on you Crazy Diamond. I really like the Piper at the Gates of Dawn so an entire album dedicated to Syd Barrett sounds pretty good to me but the line in pts. I-V where Waters sings 'Come on, you stranger, you legend, you martyr, and shine!' is like, empowering, or something.
And from second best album of Bob Dylan Blonde on Blonde, in Just like a Woman, where he sings 'With her fog, her amphetamine and her pearls' and another line from that song 'It was raining from the first, and I was dying there of thirst, so I came in here'. He sings it with a really nice tone live at the Concert for Bangladesh, he also does a really good performance of 'It takes a lot to laugh, it takes a train to cry' there, too.