So for me, putting my games in order has been like this:
1-10: Pretty easy. I know my favorite of favorites.
11-20: A little tougher, but there's some games that have really stood out and are unforgettable.
21-30: Now it's getting tough to place them. I don't know if I'll ever be truly satisfied with my positioning!
31-40: Took me about an hour to be satisfied with this grouping. The rest of the great games are really competing for a spot!
41-50: I've got about 20 more amazing games that I love... and 10 spots. Guilt has set in. Forgive me games that didn't make it!!!