If you've been reading this blog for a while  you are aware that I have more than a passing fancy with cereal.
Since it is unlikely that you have ventured into the realm as much as I, here are some combinations involving cereal that you might not have thought to try:
1) Froot Loops and Cap'n Crunch: This combination occur earlier today because of two factors. First, I wanted to finish off the box of Froot Loops that had been in the pantry forever and secondly because the Bear ate half the bowl that was left. 
Turns out it isn't that bad. Actually, I would call it an improvement on both of the base cereals. A problem with Froot Loops is that the flavor is overpowering. With the Cap'n Crunch in their the flavor was diluted and quite enjoyable. A problem with Cap'n Crunch is that it can tear up the roof of your mouth. The presence of the Froot Loops eliminated this.
I suspect to get the best out of this combo you should mix the two cereals together first.
The resulting combo wasn't anything amazing and will likely be forgotten never to be eaten again, but there's one less box in the pantry and I enjoyed consuming it.
Froot Loops and Cap'n Crunch: B
2) Cocoa Krispies and Honey Smacks: Unlike the first entry, this is actually a combination that I intentionally eat from time to time. It tastes best when you do not mix the two cereals but have a bottom layer of one and a top layer of the other.
In truth, I've had this enough times that I've come to realize that it actually matters which one is on the bottom and which is on top. Unfortunately, I can never remember which goes where. Right now my gut instinct  is telling me that the Krispies go on bottom and the Smacks on top.
You can also sub out the Honey Smacks for Golden Crisp. Though Golden Crisp is a bit too sugary sweet for me and I don't prefer it. And you can sub out the Cocoa Krispies for Cocoa Pebbles. That swap gets you a slightly different taste that is just as good, but does subject you to the problem of Pebbles which is that they quickly turn to mushy paste in the bowl. 
The resulting combo is really good and different enough from the originals that it stand on its own.
Cocoa Krispies and Honey Smacks: A-
Frosted Flakes and any type Ice Cream: It's possible you've ventured into the "cereal on top of ice cream" genre. You almost  can't go wrong. But in my vast experience, the king of ice cream toppers is Frosted Flakes. Any variety of Frosted Flakes will do, but as previously stated, I prefer the Aldi brand. 
Granted I technically haven't put them on every type of ice cream in the world, so I can't testify that they will do much to help out your Pistachio Nut,  but they are solid additions to the many varieties we frequently buy.
Frosted Flakes and any type of Ice Cream: A+
4) Grape-nuts combined with anything: Grape Nuts are guaranteed to completely have no effect when paired with anything else. That is, as long as you leave the Grape Nuts off and just eat the other thing. Because let's face it, as previously stated Grape Nuts are disgusting.
They might slightly improved the taste of a bowl full of cold poison, but I'll never know for sure.
Grape Nuts combined with Anything: F
 - Or for just the last seven posts.
 - It is also the inspiration for this post.
 - Ha!
 - The solution is either eat really fast or eat half a bowl at a time.
 - Note the "almost".
 - Here is why.
 - But then I suspect nothing will.