For the freshest possible cup, choose whole bean and grind just before brewing. Coffee begins losing its aroma and flavor within minutes of grinding. Buying whole bean and grinding at home preserves everything that makes fresh roasted coffee worth it.
Pre-ground is still far fresher than anything on a grocery store shelf and is a great option if you don't have a grinder yet. Either way you're getting coffee roasted as fresh as possible, not sitting on a shelf for months.