Lennon. His voice had that quality that could send a shiver down your spine, even after you've heard it a million times.
In the end, to me it's what music is about. Paul was probably a more consistent songwriter, a better musician, more diverse in his talents, and he wrote some amazing songs. But his voice never got through to me the way Lennon's does. The guy could sing about reading a newspaper and it still cuts right through...