A stand alone Blu-ray player is good but I heard that it's very complicated to update the hardware when needed. But it's easier a lot for a software in case you already have an BD drive.
As for the recommendation, there are several available including models from Buffalo, Samsung, LG, ASUS and Sony. The software is Macgo Blu-ray player. According to my playing experience, this player is worthy of trust in Blu-ray playback. There is watermark trail version after all.