Report or Account View: Accounts without Open Activities or no activity in the past 90 days

Report or Account View: Accounts without Open Activities or no activity in the past 90 days

I need to run a list of accounts assigned to me that do not have an open activity assigned to it. 

I also need to run a report of which accounts I have not completed an activity for in the past 90, 120, 180, etc days.

Can someone help?