I stand by Creationism with God as the Intelligent Designer. There had to have been a cause for the Creation and there are too many varieties of things, that had to have a mastermind behind that. One most basic of organism expanding outward into all other different types of things without a designer doesn't get my support, personally.
Just because something exist doesn't mean there is a creator. For us to assume a creator exist we have to have evidence to support that claim. The fact that something is complex, by itself, doesn't qualify as evidence that a all powerful being exist. There's no logical deduction involved in that argument. It basically boils down to:
The world appears complex.
Therefore an all power deity not only exist, but is the same deity described by this 2000 year old book that men claim came from god and no other possible explanation is right and my explanation is the right one only because I say so.
The jump from complexity to god is already a big one, but to then go beyond that and say that it has to be
your god is just ridiculous This is also ignoring the obviously fallacy of your logic. Evolution isn't an idea based on complexity, it is an idea that is meant to explain complexity. We didn't come up with the theory by saying: Complexity, therefore evolution. Instead the argument is: Evolution, therefore complexity.
The idea of evolution came from the observations of things around us (much like your creationist conjecture) but the theory came from logical deductions based on evidence. We have biological evidence (such as DNA) that shows evolution happens, we have evidence of of natural selection (thanks to fossils and of the like) which shows that macro evolution happens, we have categorized the many species of this planet and organized them to show that evolution is a good explication for this complexity, and even after all of this we don't assume evolution is absolute truth since all theories are not set in stone. There's plenty of evidence out there, so much so that there are entire careers of thousands of scientist based on its study alone.