I have a Mame cocktail cabinet and purely in the name of research I just went and had a look; I use MameWah as the front end which enables the use of lists to group games. The list names are self explanatory and games are only placed after careful consideration. The following are my stats;

Total game count: 2903
"All Time Indisputable Classics": 99  games
"Worthy of Further Investigation": 122 games
"Girlies Games": 11 games

So I'd say 60 isn't quite enough but a thousand is too many.