What's the best way to setup a company whereby the founder always has control and the final word no matter how many partners he brings in? What are the disadvantages of the various setups?
So you have a range of options for keeping control. These will vary by legal system and country but in general:
People who get involved in startups like to have control over their own destiny (almost regardless of the outcome) or at least be able to contribute to it ... your always holding control means they have lost one of the key motivators for joining you in the adventure.
The harder path
Pick your partners well and keep the relationships strong between them, talk through everything and let everyone have their say. Collectively, on average, you will navigate better and work through more issues than you ever would alone ... but people need to have their say. Its harder to do, but better if you can work it that way.