You should watch:

The Arsenal of Freedom

This was episode number 20 of season 1.

The following characters appeared in this episode:

(credit only)Wesley Crusher

(as Julia Nickson) Ensign Lian T'Su

Captain Paul Rice

Captain Jean-Luc Picard

Chief Engineer Logan

Counselor Deanna Troi

Commander Wiliam T Riker

Doctor Beverly Crusher

Lieutenant Tasha Yar

Lieutenant Geordi La Forge

Lieutenant Worf

Lt Commander Data

Lt Orfil Solis

The Peddler