There are hundreds of alien species that populate the Star Wars universe, and you can have them all, in minifigs. Star Wars Lego minifigs are some of the most sought after and well made Lego minifigures.
Naturally, the most highly demanded minifigs are those of the main characters. Iconic figures like Darth Vader, Princess Leia, Han Solo, Yoda and other characters that have played a major part in the Star Wars universe have a solid following among fans, development minifigures of their likenesses very sought after. Some characters even have variations. Luke Skywalker is available in his Tatooine clothes, Rebel Pilot Outfit and his black Jedi robes as seen in Return of the Jedi. Padme Amidala is available in her royal garments, her white assault of the Clones tights and the senator's robes seen in Revenge of the Sith. Darth Vader, despite not having costume variations to his iconic Sith wear, has seen assorted incarnations as well. As Anakin, he appears as both a padawan and a Jedi Master. Naturally, the Siths and the Jedi minifigs are armed with Lego light sabers.
Lego
Side characters like the Gungan misfit Jar-jar Binks and Zam Wessell are also portrayed in minifigs. These characters, with their own unique backgrounds and stories are also used and collected by many Star Wars fans as they deepen the climate of any scene. From the assorted Jedi Masters who sit at the council to the bounty hunters in Jabba's lair, these figures are also foremost to any collector.
Finally, there are the unnamed figures. Though they do not describe any exact character, their nearnessy adds that final touch of authenticity to any scene. No Coruscant set would be faultless without imperial guards and the coliseum in Geonosis would not be without the many Jedi knights who fended off the droids.
Collecting Star Wars Lego minifigs can be a petite daunting when finding at the estimate of minifigs there are. The best idea would be to secure those which are integral to a singular set or scene. A Kashyyyk diorama while the clone wars would not be without a fair share of Wookies and clone troopers, as well as the Jedi scholar Yoda. Setting a scope and range to the frame you are collecting can help you keep track of what you need.
Keep a checklist of minifigs. While having duplicates of a singular minifig would be good -particularly for the clones and storm troopers- it would be a waste to accidentally buy two Boba Fetts because you forgot to count the minifig that comes with the Slave One spaceship set. Keeping track of what you have and do not have will help you secure using fewer resources.
The best advice about collecting minifigs is to start with the characters you categorically like. Minifigs are worth collecting on their own, independently of any set or scene. If there is a character or set of characters you like and would enjoy having, then make it a point to seek those out first.
Star Wars Lego Minifigs - Figures of the Force