Well, the Xeelee Sequence is full of ridiculously different minds. From the moment you learn why nobody has actually seen a little Xeelee in a little space suit, to little things like the Silver Ghosts, who are actually close enough for us to engage with, but so alien that the term for the member of their species which interacts with other species is "Sink Ambassador", because space is just a heat sink to a race from a planet with a dying star.
Then there's the Qax, which is like how we build logic circuits with minecarts, except the minecarts are bubbles above a near-boiling mudflat, and the logic circuit is self-aware.
Then you get the Culture Minds which are so powerful that their POV character is generally just an avatar that they're delegating tasks/interactions to, and said avatar is still generally smarter, faster, and so forth than a human, which representing just a portion of the full awareness of a given Mind.
There are lots of ways that you can conceive of which would fit the label "superhuman" along the intellect/insight/memory/problem-solving/etc axes. Understanding what it would be like to actually be out there at the far end of that brainpower scale is a far more difficult question, but it's one we have to deal with if strong AI turns out to be a viable route in the near future.
For reference:
*Weak AI: capable of simulating a mind, emulating responses of a mind, and do anything short of actually being self-aware and intelligent.
*Strong AI: capable of actually being a mind, responding as a mind would, and exhibiting full self-awareness.
Those aren't hard and fast definitions, and I'm totally open to different ones, it's just a general example of what I mean when I use those terms right this minute.
Would be neat to have a story like that where you only introduce humans near the end, after the audience gets a chance to get used to the new normal. Then suddenly there are humans and everyone's like "whoa those things are weird."
I have read a couple of different stories like that but can't think of one off the top of my head.