My answer is obvious with Zone of the Enders 2ND Runner but very close to that is Snatcher IMO tho IMO I think both are better than MG but that's just me.

BTW this is released games not demo's of unrelased games.

If none of the poll options suit you here is his wiki. https://en.wikipedia.org/wiki/Hideo_Kojima

He also worked on Beatmania,Boktai series,Penguin Adventure,Lunar Knights and more.

Yes. His DNA is still in ZOE2

Suikoden 2

He didn't work on that game as far as I know

My bad. I missed the kojima part. Thought it was any konami games apart from metal gear

Well, thats easy for me. Its Lords of Shadow. I'd rank that game above most of his MGS games.
And yet you didnt even put it in the poll.

My vote goes to ZOE1.

Never heard of any of these games and I'm sure there a plenty other people who are also in the same boat.

That’s because it’s not a game by Kojima. Kojima Production only helped with development.

If you're ignorant to his work then why post? A lot of people played those games. Policenauts theme is in the intro of Metal Gear Solid. Policenauts has Meryle. Snatcher has a Metal Gear before Metal Gear. ZOE,Policenauts take place in the MG universe long after the MG games happened. I don't mean this next sentence in a malicious way but Nintendo fans are the most ignorant fanbase as a general rule to games/series outside Nintendo. So this isn't surprising.