Depends.
If Metascore is the measurement then I wouldn't buy the system with only 100 games since top 20 would be not enough games I would like to play (I mean, I don't want to play every game just because it has a great score)) and in the bottom 80 would be probably also not enough games for me.
Personal taste then top 20 as long as it's really enough games for me.to justify the purchase of the system. Maybe even my top 20 would have already some games I wouldn't like that much 
1000+ games then probably top 20 personal taste and also with Metascore as measurement. The best 200+ reviewed games, I think that would be enough for me even if I would miss many games not as good reviewed but interesting to me.







