ReTool. The fact it’s interactive and scriptable with JS makes it better IMO than all other BI tools I’ve seen.
I'm deeply confused as to why people are downvoting this - maybe it's not a suitable answer for many use cases (it doesn't look like it'd be my thing most of the time, certainly), but I'm aware of enough very happy ReTool users to assume it must be useful for at least a decent subset. Can somebody please explain why they consider this to've been a terrible answer?
Just guesses.