so despite a number of quality compositions from Marr, Street, Whyte etc, it's Mark Nevin's that gets the most votes (altho King Leer hasn't fared so well!). his post Kill Uncle stuff was getting really good, wasn't it? I read somewhere that he didn't realise that Moz wanted him to provide effectively complete pieces of music until later in their songwriting partnership.
what is it about keyboard-based songs that seems to result in higher quality material? my guess is that it's much easier to get away with writing mediocre songs when using a generic indie guitar arrangement. three or four chords, an indistinct guitar line, a couple of vague melodies and there you have it; Father Must Be Killed! (and countless other post-Vauxhall solo songs).
when a song is based around a piano part, perhaps the backing track demands a stronger melody from its composer...