Definitely a difficult question to answer. Most of my spirits are quite active but in different ways. Most are communicative by pendulum some more so than others. I would say my Unicorn, Fae, Heaven Hound, Kitsune, Leprachaun and Dragon Shifters are recognizable outside of the pendulum by moods, unusual bouts of luck and orbs. Unicorn and Kitsune are very witty and have an incredible sense of humour. My Fae manipulates the radio. Heaven Hound produces orbs on the camera. Dragon shifters produce visual orbs. Leprachaun when he is properly given duties to fulfill brings in an unusual amount of financial luck. Also I can not leave out my Throne Angel, who doesn't really communicate with me however my entire spirit family talk about her and are very happy she's around. Based on my own abilities to perceive activity I don't know if she's someone that could be included in the list, however she is definitely present and a great source of aid for my other spirits.

So I thought about this thread for awhile...I have over 50+ spirits in my spirit family but my MOST "active" is my human male witch BUT... besides that I think my succubus and incubus are. It's strange to say, but I feel my ubi appear to me more than any of my other spirits.. I have a lot of nonhuman spirits and entities, and a lot of human spirits with me ("haunted" dolls), but I feel maybe the incubus appears to me a lot since I did a custom conjuration of one for a triumvirate vessel from CH quite long ago.
I think because I am in a type of relationship with the male witch spirit, it's kind of natural and obvious the manifestations and appearances would happen more towards me (at least that's what I think).

My most active is one of my human spirits :p