I've seen numerous games go down the pan when certain players derail the plot, either making it PC vs GM, or making the game more about their ludicrous choices. It might seem overly harsh turn of phrase, but the majority of players decided to launch a space ship at a Blue Sun base, in a game of Firefly, which seemed at the time out of character for the setting. Which for those not familiar with firefly, would be like hi-jacking a star destroyer and launching it into the Deathstar.
The players had been making this sort of brute force decision making throughout the campaign, sometimes with aplomb (taking out 8 Alliance troops without a casualty, in a way that would make Mal jealous), othertimes ruining what I thought could have been interesting games, that the GM had obviously spent a long time preparing for.
For some context, Launch a ship at the enemy had been the solution for three games that campaign out of about 6 sessions, each time the GM losing more and more patience eventually losing interest in preparing for the game.
TL;DR
How, as a player can I step in and help keep the game interesting for everyone and the plot on track?
Answers of find a different group aren't too helpful, as it's a university based role-playing society group, so we only get to chose the game, not our fellow players.