Star Trek Voyager gave fans some iconic and beloved characters, such as Seven of Nine, Captain Janeway, and Tom Paris. However, the Doctor is a character that is arguably THE most loved by Voyager fans and Star Trek fans in general. He started out as a piece of technology that turned into one of the most loved members of the crew.
He is one of the only characters who viewers see develop throughout the series, and the situations he found himself in throughout the show's run varied from hilarious to dangerous. He was always able to provide a laugh in any situation through a facial expression or sarcastic comment, and his friendship with Seven provided an excellent commentary on various issues.
While he hit many bumps in the road in his attempts to become more than a mere piece of technology, his determination and persistence meant he eventually did exceed his programming. His is a story of self-development that occurred before self-development was a buzzword, and took place in an area of space never before explored.
Like most of the other main characters, the Doctor got many storylines, but not episodes that seemed to feature him centrally. However, the ones that did, few though they may have been, were some of the best of the show's seven-season run.
The Doctor got his first major storyline in this season one episode, in which an increasingly complex situation turns into a life or death situation for him. It begins with him being activated after a red alert is issued. B'Elanna then enters sickbay injured and explains that the Kazon have attacked the ship.
He then goes to the mess hall to help Neelix defend against a stray Kazon, and during this encounter, he begins to bleed and feel pain, which as a hologram he shouldn't be able to do.
Enter Lieutenant Barclay who explains to him that he is actually Dr Zimmerman, the creator of the EMH, who is trapped in a simulation due to a radiation surge. The race is then on to end the simulation to prevent the Doctor from dying from radiation poisoning.
Another twist is thrown in when just before the Doctor is about to destroy the ship to end the simulation, Chakotay appears to tell him he IS the EMH and that destroying the ship will ensure his program is lost forever. This explanation ends up being true and a malfunctioning holodeck is found to be responsible.
The tension and twists in this episode keep viewers interested and questioning everything the whole time. It's the Doctor's first solo plot and it delivers, as he has something similar to an identity crisis, as he does not know for sure who he really is. The inclusion of fan favourite Barclay also gives this episode a boost.