10 MORE Star Trek Moments That Broke Our Hearts

10. Goodbye Sim - Similitude

Tuvix is often cited as one of the great debates in the Star Trek fandom. There's certainly merit for it - did Janeway do the right thing? However, Similitude occupies a similar theme, though Archer's actions are a little harder to defend.

Tuvix was created accidentally and was a combination of two other living creatures. Sim was created for the express purpose of fuelling Trip's recovery, with Archer fully understanding he was creating a sentient being to farm for parts.

Similitude works so well because Conner Trinneer brings Sim to life, despite the audience already knowing - and rooting for - Trip to live. Sim is certainly a sacrifice, one made more painful by his complete inability to affect his fate, despite his will to live.

The final scene - with Trip standing over his own clone's body - is heart-wrenching. We also feel for Archer who, though directly responsible for a sentient being's death, has saved not only his friend but a vital member of the crew in the name of the mission.

Janeway had it rough as she was forced into an unwinnable scenario, whereas Archer knew exactly what he was doing. Wherever one lands when considering his guilt, there is no doubt that Trinneer and Scott Bakula play the hell out of that ending.