There seem to be three main schools of thought when it comes to sci fi
crazyintheeast
The Star Wars one: Where the conflict might be on a galactic scale but everything is ultimately decided in a duel between two people with opposing ideologies
The Star Trek one : Where conflict is resolved through diplomacy and finding common ground
The Stargate one : Where you kill your enemy, you blow up his ship, you blow his planet, your blow up his solar system and you make sure you wipe out his entire species from the galaxy*
*should you find his species in another galaxy repeat the process until you achieve complete extermination
bethanyactually
The Pacific Rim one: Where humanity bands together to build giant fucking robots to smash the invading aliens to bits.
blackmelange
The Farscape one: Where you fall down the rabbit hole, befriend a bunch of fugitive criminals, royally piss off The Authorities by associating with aforementioned criminals, fall in love with an emotionally distant but crazy hot exile from said Authorities, and proceed to drink, drug and actually destroy your way across the galaxy.