This is such a big question...
with so many facets to it.
Songs can be the 'best' for communicating a feeling, for universal appeal, for summing an era, for giving voice to a certain concept, for explaining a point of view or idea, an arresting melody or just having a undeniable and unbelivable groove.
I myself gravitate to the big 'commercial' writers, from Tin Pan Alley-era, but also to the songwriter/producer craftsmen of today, like Lyle Lovett or Vic Chestnutt.
Can't name ONE best song.
Anyway, for universal appeal, for a killer melody, and peerless production, I have to go with the Drifters' version of Carole King's 'Up On The Roof'. Anyone can relate to that, the song has been on the radio for 40 years, and it's been covered zillions of times.
For an all-time classic song, 'Ain't Misbehavin' by Fats Waller just kills. You can play it simple or as complex as you like, it's hummable, and the bridge - the way it builds on the other parts of the song, but it just lifts it to a whole other level.
For pop music, I too have to go with Steely Dan, but 'Peg'. Pop music made by a bunch of condescending jazz wannabe's, with LA session guys. The subtle funk bass, the not quite anarchic guitar solo, and bizarre multi-layered harmonies. Pure bliss.
'Good Vibrations' by the Beach Boys, as a piece of studio craft - the song is essentially drivel, but multi-layered ear candy in falsetto harmony, the ripping cello break still excites me, and they actually got a musically useful sound out of a Theremin!
And for a good folky campfire song, you can't go wrong with Sam Stone by John Prine. What other song can has a sing-along chorus like:
"There's a hole in daddy's arm,
where all the money goes -
Jesus Christ died for nothing,
I suppose
Little Pitchers have big ears,
don't stop to count the years,
and old sweet songs,
they don't play long
on broken radios"
Overall song that's I've actually used the 'repeat' button on the CD player - Be My Baby - the Ronnettes. Sheer teen-angst sound. Put it up against 'Smells like Teen Spirit' anyday. Try them back to back at the same volume!
And about picking music from the last 10 years or so... I feel intimidated by this huge backlog of music that I have to sort through from the last 15 years or so. There's so much coming out all the time, and it seems that music is much more fragmented and everything in it's own niche. All I know is that I'm sure that top40 radio was never this bad before, and so many types of music aren't on the radio at all, or on specialist tiny stations, or internet stations. These damned modern times!
