The question of how many games is too many games has an honest answer: it is too many when you have games you have owned for years and never played. Unplayed games represent unrealized value in both money and experience. A collection of 50 well-played games is worth more than a collection of 200 games with a 30% play rate.

My culling process: if a game has not been played in two years and I cannot remember the last time I genuinely wanted to play it, it leaves the collection. Exceptions for games that serve specific situations (large parties, mixed age groups) that occur infrequently.

The games I have culled that I regret: none. The games I kept that I thought I should cull: Twilight Imperium (plays rarely, but those sessions are events), Talisman (not a good game, but creates a specific social experience nothing else replicates).