Ask HN: Which keyword research tool do you use for AdWords campaigns?

I haven't run an AdWords campaign in probably years. We are working on a new product and think this time SEM might be a better fit for us.

Could anyone help with some suggestions as to what I can use to research and identify the right keywords to target with the AdWords campaign?

*Just launched a quiet little Beta so I don't have much info on SEO keywords or much activity to measure.

Thanks in advance!