[Greylocks]

Criteria for the answers.

You must own the gun, not have simply read or heard about it. That way your comments are based on real facts. It should be a production model, not something completely exotic or rare.

The gun must be an AEG (for now, to simply narrow the field and keep this manageable).

The gun must be reviewed in it's "stock" form; non-upgraded, from the factory.

The attempt is to find the most bullet-proof recommended AEG that has the least amount of problems, or none.

It must be easy to maintain without headaches.

It must work perfectly as it is right out of the box.

The parts needed for it to operate (magazines) and other factory-attached parts (like red-dot sights and such) must also be problem-free.

Again, you must OWN this gun, not give internet review links or use hearsay.
If this works, there will be another thread for handguns and spring/sniper rifles.