At this time, little is known about The Entities.
Recent sightings at Memory Alpha, Memory Beta, and Subspace Comms Networkwarrant futher investigation. Possible connections are being explored with the Bajoran Prophets, Koinonians, Thasians, Devidians, Organians, and others. Additional findings will be reported here in the near future.
I guess my favorite series is The Next Generation. I was raised on the original; my dad is a big fan of Kirk and Spock, and I have a little brother who is still wild about DS9. I like all of them to some degree, but they really hit on all cylinders with Picard sometimes, IMHO.