I loved Reviving Bionicle...but I typically prefer more serious oriented series. And on that note;
Heroes of Ora Nui was literally the first Biotube series I saw. I loved it, up until I found out it had been cancelled, and was subsequently really, really sad. It still holds a special place in my heart because of its origin, even if it may not be the best series.
Apart from that, the Hydros Chronicles and Society of Guardians were really good IMO, until they....were also cancelled when the uploader went offline.
I also liked what I saw of Bionicle Destiny from Shade 2800, but have only watched the first episode so far.