I have a radio show and here are a few comments from that perspective:
If you want your CD to stand out in radio libraries and thus have a better chance of playtime, 1) put 'em in jewel cases (easy to read title, artist etc.), 2)put playlist on back in as large letters as possible, on a contrasting ground and PUT TRACK TIMES THERE! The inside sleeve needn't be fancy but as much info. about artist(s) and material as possible helps the poor bloody programmer. Lastly, if you want your CD to really stand out on shelves or bins put something distinctive on the spine, eg three large blak dots, two red triangles etc.
Hope this helps, Malcolm