I'll go as far as panspermia, which offers it's own infinite regression quandary. But as far as engineering goes, we're a mess.
Three examples: the retinal blind spot, the laryngeal nerve structure (an inefficiency compounded in the giraffe) and the merger of the trachea and esophagus which has killed millions.

@birdingnut mentions the Sumerians... their ancient texts and pictographs show their multiple gods as coming from the sky, along with accurate depictions of the solar system. They may have very well been visited by an advance group of humanoids, who knows.

Genetic evidence does suggest manipulation of some kind, as around the time hominids' abilities and technologies VERY quickly evolved was the same era when two pairs of our chromosomes morphed into one, giving us our 23 pairs; other primates have 24 pairs according to the chimpanzee genome project and other sources.

The smoking gun so to speak is that we have hundreds and hundreds of chromosomal "mistakes", or mutations (Downs Syndrome for example). Other primates have little to none according to investigators. So were we tinkered with? There is circumstantial evidence to suggest so. But it's just that - circumstantial. It's an entertaining premise for sure...

I have considered the possibility and concluded not likely given that aliens would have had to have overcome the problem with faster than light travel.

Not me. Probably not anyone else either, if I had to guess.

It would behoove you to actually STUDY how evolution works. Belief is the antithesis of reason. It may comfort you to believe that you are special, in that you were lovingly designed by some unspecified intelligence. This would give you the comfort of feeling superior to the other living creatures of the planet but it's just an insecurity expressing itself. What, after all, is the difference between your beneficent alien and any religion's god? Sorry to burst your bubble but we evolved here with no outside influences. Instead of trying to separate yourself from other beings I would recommend you try to find the joy of your direct kinship with every living entity on the planet.

Who created them?

No only do I not believe it, I think you are a danger to yourself if your beliefs can stray so far from what is plausible.

"Extraordinary claims require extraordinary evidence" - Carl Sagan

It is fun to think about, but there isn't enough evidence to support it.

What suggests this as likely to you? It sounds awfully wild and not something I'd accept as even possible without much more extraordinary evidence than I have ever seen for it...

Evidence? We have ample evidence through the fossil record and now genetics to state with some confidence that the line of emerging homo sapiens sapiens is continual and that there was no 'sudden' change in our makeup. If you have evidence to the contrary, I suggest you submit it soon because you will be a shoo in for a Nobel Prize -- perhaps several others.

Now, to this business of believing in Ancient Aliens. As far as I can tell, that is essentially the same thing as believing in some deity. I say essentially because at least the notion of aliens is not in the realm of the supernatural and is thus a possibility. The problem is that we have no real evidence for them, but we have mountains of evidence for our continual evolution without intervention.

Again, if you have evidence you will be wealthy and famous beyond imagining. Hurry, man, hurry.

I have always loved crack pot ideas. I read several book on this one, years ago. It was fun. Then I read a book debunking the idea. That was more fun. I tend to be a skeptic but love to play with unusual ideas.

Why do you believe this?
Do you think those ancient aleins were created by older ETs, who were created by even older ones? or that the ETs that made us evolved without intervention?

I see no reason not to assume we evolved without intervention, since some race must have at some point. But happy to possibly change my view after hearing your reasons.

What kind of proof do you have to support your belief? Have you met an Alien, seen a spaceship, is there any research that has been published in a respected scientific journal?

There is no empirical evidence. Anecdotal,l evidence is not proof , So it is not impossible that we have been visited but we need evidence, conjecture is not proof.

I believe in Marvin The Martian.

Not me.

Why do you think we were created? We could be the aliens themselves after a long period of little contact our technology knowledge has degraded with time. We are now just catching up again.

While more plausible than a god, still highly improbable.

What evidence do you have to support these beliefs?

In my travels, Peru specifically, the Quechua that have lived for centuries around the Machu Picchu area and the Inka Trail and other areas (where us tourists visit ruins) believe that the very tall stone steps were built by the Ancient Aliens who were Giants. From their POV, being smaller in stature, you can see why they'd think that. Again, "religion" is from a human POV - when it can't be explained, it must be a god/dess or something that provides a comfort level that not knowing, or being ambiguous, cannot.

Maybe we're living in a simulation? Puppeted by aliens.

I doubt it but have open mind about ets

Well, it isn't IMpossible.

There is a tendency to poo-poo ancient writings, but there must be some basis of fact.

I have trouble getting over the closeness that Genesis has to the stages in the creation of Earth. How did they get so close ? If you google Genesis and Science you get a variety of obviously biased matches. The info could have come from the say, Sumerians.

But, while you may consider it a possibility, I find it hard to "believe" it without some serious, peer reviewed evidence.

I believe that life exists somewhere else in the universe because what seems more likely? The idea that aliens exist or the idea that there's this universe of mind boggling size filled with billions of galaxies each with billions of stars which in turn almost all have planets but they're all dead and then all the sudden we happened. As if we're some fluke of nature. If it CAN happen here then it CAN happen in other places in the cosmos assuming that there are places with similar conditions.