I've been hanging onto the Eisenhowers and below. Then maybe 2000 and 2001 Sacagaweas. I'm also collecting the presidents, but for someone that isn't maybe hold onto some of the lower mintage ones. Really, it is still probably too early to tell.
Nothing wrong with holding onto them. I would check all the Sacagawea Dollars to see if any are the Cheerios dollar. See this link.
Susan Bs: 1979 - look for wide rim 1981 - only in mint sets Probably could hang onto all the years considering they were only made from 1979-1981 and once more in 1999.
