Self improving superintelligences that have had thousands of years to self-improve so they are near god like:

"I am a Culture Mind. We are close to gods, and on the far side. We are quicker; we live faster and more completely than you do, with so many more senses, such a greater store of memories and at such a fine level of detail. We die more slowly, and we die more completely, too."

Of course, in the Culture universe there are things far more powerful than Minds - the transcended entities that still dabble in the base reality - such as the Dra'Azon. Although I seem to remember someone, probably a drone, snarkily referring to it as senile.