Who is your favorite artist/composer?
My all-time favorite composer is Bela Bartok and immediately behind him is Jerry Goldsmith. Bartok died in 1945 and Goldsmith in 2004. Both are worth your time if you don't know their work.
Other than them, it's incredibly hard to answer that! There are many wonderful composers throughout history and alive today. Some of my colleagues who inspire me (who I also feel fortunate to call my friends) include Eric Whitacre, Michael Giacchino, Garry Schyman, Christopher Tin and Gerard Marino.