The North American format
The UK one is fine but I prefer the idea of houseguests having to save themselves with competitions (HOH, veto, anything extra) or through influencing fellow houseguests to save them. I'd rather that than a popularity contest (even if it can be entertaining). And when it comes down to it, BBUK is kinda just about who has the biggest fanbase going into the show with maybe some exceptions.
Both are respectable formats though. I've never given BBAUS a fair chance yet
