Here all the 90's era games I though would be permanent fixtures in my collection two years ago. Out of 7 games, only 4 I still consider keepers:
CFTBL - perfect game for theme and casual players. HEP restoration, not going anywhere.
MM - tied with Creature as to which game will leave last. Bought NIB and family favorite.
NGG - still don't get tired of it. Paid almost nothing for it in 1999 which is a consideration too.
TAF - was never interested in the game until I sold Monopoly to get it. Dated, but fun. Position in pinball history alone probably enough to keep it.
MB - Already sold. Didn't last long. Just didn't keep my interest. It's slot is waiting for AMH.
SC - will probably go to make room for Pat's JJP game.
SS - not as interesting as it used to be. Will probably go whenever I sell Elvira.
AFM is on my wish list, primarily as a companion to RFM, but as long as space is a consideration, interest is fading over keeping room for a future NIB game.