Haven

On the way to Haven, a peaceful, remote planet, the Enterprise welcomes Lwaxana Troi, the Counselor's mother, who has arranged for her daughter to marry a man called Wyatt Miller. Deanna is reluctant, and Riker is more uncomfortable than he admits. Meanwhile, a derelict ship carrying plague survivors approaches and causes serious concern.
This is the first appearance of Lwaxana Troi, a flamboyant and domineering telepath who became a recurring comic and dramatic presence in the series. The episode mixes romance, family conflict, and a mild threat. It also shows the Betazed custom of weddings in the nude, which fans still joke about. Haven is the kind of lighter hour that gives the crew room to breathe.