ArkivMusic is an online classical music retailer that distributes their recordings via CDs, DVDs, Vinyl, SACDs and Blu-Ray formats. Their inventory is the most extensive of any I have found for every genre of classical music—over 2300 in their current catalogue. One can search for music by categories such as Composers, Conductors, Performers, Ensembles, Labels and Opera. New Releases and on sale items are always featured.
ArkivJazz is the counterpart music retailer but for all styles of jazz. Music is distributed via the same formats as the classical site but there are also several interviews with artists who have new releases as well as a Podcast series available. One can pre-order upcoming releases here as well.
I’ve had nothing but good experiences with these retailers. Highly recommended!