Honestly I don't think there is one artist that shaped my taste the most. It's a combination of a lot of things.
Like every white kid, I loved Eminem when I was younger, and he is what got me interested in both hip-hop and music in general. My dad was always listening to dad rock in the house and car and that's what got me into guitar music. MF DOOM (Madvillainy in particular) is who got me interested in music outside of the mainstream, and I just went down the rabbit hole from there into other genres.
Most recently it's been My Bloody Valentine and Sweet Trip. Of course I loved Loveless on first listen and that made me check out other shoegaze artists that I now like as well (Slowdive, Ride, Swirlies, etc.). Sweet Trip is more of an anomaly. Their second album is incredible and has quickly become one of my favourite albums of all time. I'm now desperately seeking more albums like it.
As far as the music I make goes, of course I wanted to rap like Eminem when I was younger and that led to me making my own boom bap-style hip-hop beats. I still do that but now the stuff I make is mostly an amalgamation of what I'm listening to at the time. I'm going to start up an electronic/shoegaze band with my friend as soon as I'm not horrible at guitar.
What?