1) Beethoven, beyond a doubt, for sheer innovation and his ability to convey such a huge range of emotion, from heaven to hell and back, always back, never compromising for the easy answer, always surprising us with the unexpected and often shocking.
2) Schubert, especially late, just because its that unique, sweet, vulnerable, happy, morose, angry, serene voice where sweetness always wins out, and I say thank you for your beautiful soul.
3) Scriabin, for transcendence in so many ways -- compositionally, technically, emotionally. Transcendent, radiant, vibrant, decadent, sensual...fusing the erotic and the mystic like a tantric guru.
4) Haydn for sheer joy, playfulness, fun, and constant surprises.
5) Mozart for beauty of line, subtlety of feeling, refinement of sentiment. clarity of expression.