Jonathan Coulton
 

Has anyone heard this guy? He's a hilarious sci-fi/comedy music artist. I just started listening to him earlier this month when Slice of Sci-Fi recommended him and played a couple of his songs.

His official website.

You can listen to most of his entire songs in free streaming format here, and he requires a donation (usually just $1) if you want to buy the MP3s, but if you can find a song with a gif that's shaped like a happy face next to it, it means he was generous and is offering the song for a free download.

I recommend checking out "Skullcrusher Mountain" and "Re: Your Brains" as good places to start.