Also, okoume because of its light weight. Shows up in kayaks, as well. Fischer has used a lot of okoume/poplar laminates, I believe.
Maple and hickory are used as well, though not widely these days, it appears.
Since fiber composites, metal, rubber, epoxy and so forth also impart their own qualities to a ski, I think a lot of mixing and matching goes into wood selection (including laminates of two or more different woods) to produce the combination of qualities the designer is looking for in conjunction with other materials being used.