I couldn't choose just one so here’s my current top five.
1, Captain Jean-Luc Picard
Oh captain, my captain. My favorite spaceship captain, Picard is a real Renaissance man. He’s not “just” a diplomat and a leader of soldiers. He’s also interested in archaeology on various planets, he acts, riders horse, and plays a flute. He’s also dappled in painting. He must know many cultures in his profession as a diplomat. He keeps his private life private from his crew. However, during the seven years of Star Trek: TNG we get to know him very well. He’s ethical to a fault and never takes the easy way out.
2, John Crichton
Another man who lives up to his ideals. At the start of Farscape, he’s a scientist and an astronaut who is flung accidentally through a wormhole across the universe There he meets a lot of new cultures and people. His sense of humor keeps him sane even though he knows that it’s quite possible he’ll never return home. He’s brave and loyal but also quite mischievous.
Babylon 5 has lots of very interesting male characters so it’s was hard to pick just one. G’Kar is the Narn ambassador to the Babylon 5 space station. He despised the Centauri who occupied his home world for years, keeping the Narn as slaves. But on B5 he must be at least civil to the Centauri. He has a wonderful character arc through the series.
4, Doctor Emmet Brown
I love the Back to the Future Trilogy and the Doc is one of the best things about it. He’s so upbeat and optimistic all the time in addition to being a genius inventor
Magneto’s childhood was cut off horribly and he was sent to a Nazi concentration camp. Now, he wants to protect all mutants for similar oppression. His methods sometimes are questionable, but at other times, he’s a full member of the X-Men.