How many board games is enough?

I'm curious, just how many board games does one need to consider themselves well-equipped for a game night? Is it a matter of having a variety of genres, such as strategy, party, and family-friendly options? Or is it more about having a deep collection within a specific genre that caters to one's personal preferences? And what's the balance between having enough to keep everyone entertained without overwhelming the space or budget? Ultimately, how do we determine what 'enough' truly means in the realm of board game collections?