I'd say most of burgers, same as kebabs and pizza are designed for a specific region and people, specific taste. So it will be hard to find the exactly same flavour that you like because there's a big probability that it only tastes like that in your country
I would agree with that completely. I find that "American" burgers have the meat ground too fine for my taste and so I prefer the ones I get the butcher shop in the UK where it is just normal minced meat.
Also to those denouncing the fat in a burger. The fat in meat gives it a lot of flavour. Compare a fillet and a sirloin, a fillet will be nice and tender but won't taste half as good as the sirloin.
I personally like making my own burgers as well though, not because of specific ingredients or being sure of the quality. More just because they are fun to make and it means you can season it to your taste from the start. I personally like to add some finely chopped onions, garlic, allspice and a decent bit of black pepper. I also normally add some "filler" of breadcrumbs with egg yolk because I feel it gives it a nice mouth-feel. Some star anise is always nice in there too.
I actually had a dream last night that I was arguing with a burger vendor because he said I wasn't allowed a bacon and cheese quarter pounder...don't know how that turned out though because I woke up.