Ultimate Edition is the only version available for Windows and includes the two DLC (Reverie and Resurrection) that the console versions had.
Reverie DLC follows immediately after the actual ending of the game and returns to Carmilla's castle. This DLC ignores the cinematic shown at the end of the previous chapter and returns to a time near the end of gameplay portion of the previous chapter.
Resurrection DLC adds another chapter following the events of the Reverie DLC.
According to David Cox, one of the producers, the DLC were a "mistake".
About Castlevania: Lords of Shadow