Best: accordion. Easy to ignore, hard to do quirky covers, chance of an occasional shanty.

Worst: guitar. Probably some checked shirt helmet doing James Morrison covers in an affected mid-Atlantic accent. Other nominees: bagpipes (audible everywhere, very limited range of tunes), those Peruvian pan-pipe bands (how much of this is actually just the backing track), saxophone (shit instrument for twats).

NOTE: This is the generic busker thread. Specific busker chat had no place here.