When is a game Too broken? (Sunk-Cost thoughts)

I seem to do the same thing repeatedly - I get a game system and learn how to play, prepare for the game and then ultimately discover that the game is broken to the point that playing it would be unfun. But I stick with the game with the hope that it might get better with time.
Let me know so what you think - how do you solve for the Sunk-Cost fallacy?