There's plenty. Too many. Not many mentioned here so far though - although 'Heatwave' and 'The Girl with the Sun in Her Head' are up there.
I think songs that you never tire of hearing have to have some resonance in my life as well as just being great songs. Sometimes this makes them painful but still essential. A few of those for me:
Curtis Mayfield - 'Move on Up' (well anything by the great man, really) - another one that gets you right from the first drum beat
Gil Scott-Heron - 'Lady Day and John Coltrane' (makes you feel as alive as the music he's talking about)
The Beatles - 'It's All Too Much' (not a well-known track, but just simple chords, gorgeous waves of summery feedback, trumpets, hand-claps)
Bjork - 'Isobel' (crazy, life-affirming, and a huge break in the middle that opens up with big and romantic strings and beats all at once)
The Waterboys - 'Fisherman's Blues' (ridiculous oirish romanticism, but does it work? Absolutely!)
Sufjan Stevens - the whole of Illinoise (it really is a proper album)
Can - 'Mother Sky' (it's Can, what more do you want to know?)
Blur - 'Coffee and TV' (at their most beautiful)
and one by a band I am guessing most people here will not know, The Egg, called 'The Fat Boy Goes to the Cinema' - the essence of laid-back, summers in Oxford in the mid-90s.
There are a lot more.
