I am still partial to and use slimline CD jewel cases. They basically fill two giant bookshelves at my house, alhough it is very easy to slide some over to make room and file a new one in alpha/numeric order by artist/date of show. At < $0.10/each when bought in bulk, this has not cost much more (if at all) than using sleeves, books, or envelopes.
When I first started collecting (commerical) CDs, I had one of those books. A good number of those intial CDs are now too scratched to play and ruined due to being slid in and out of the sleeves too many times, without enough due care, or from dust and crap getting into the sleeves and then scratching the discs when being inserted/removed.
I have also found that many, including many of our own, are so poor at handling their media that using sleeves basically guarantees fingerprints on the disc and scratches from "normal" handling...something MUCH easier to avoid with slimline jewel cases.