OK, so drinking... and catching up.

I'm a bit disappointed. Notable omissions:

R.E.M.
Tori Amos
Tool
Alice in Chains
Pearl Jam
Ani DiFranco

Anyhoo, let's kick this off the way the 90's did. My method will be to google the billboard top 100 songs for each year, and pick the closest one to the top that I would actually like to hear.
1990: #9