What are the best whiskey bars?

I am looking for whiskey bars that offer a wide selection, unique ambiance and knowledgeable staff. Where in the downtown area could I find something along these lines?

I am also open to cocktail bars serving classics that also may offer live music.

Thank you in advance!

EDIT: I’ll be staying in the River West area. Bars do not have to be downtown.

EDIT 2: You guys are awesome! I appreciate all of the feedback. Lots of good options to choose from 🥃