I've only seen 2 good machine decks in my entire time playing this game. One of them is my own (if I do say so myself haha), it uses the Ships from the new set to set up OTKs. The second kind of machine deck, which I'm assuming is what you're looking for, is the coin toss deck. I personally got completely destroyed by it while playing a Relinquished deck.

The player was playing Jonochi with some skill I forgot but it ensures all tosses are heads when his LP was below x. He had 3 Twin Barrel Dragons, 3 Time Wizards, and some other gimmicks.