It depends on the frequency. Any modern Stern....No

All of the Bally/Williams titles- Yes I got rid of all of the BW titles except IJ because they started to get a bit too easy. Its a shame, because they have a lot more charm than the Stern titles do, but they don't get played at all.

Depends on why you are playing. If it is purely for points, then it doesn't matter. In a home environment though, a lot of times those games are single player games, and sometimes you are playing for the journey and not the score. Two of my favorite games are CV and Whitewater. I was joining the Cirqus almost every other game (sometimes twice in a game), and absolutely crushing Whitewater on a regular/gamely basis. I miss both of them until I play them somewhere else, and am reminded why I don't own them anymore. It isn't that they aren't fun games, its just they take up space for games that I haven't taken the journey with yet.