strawberry mountain: im paraphrasing here, but it's basically a cow's paradise. free range, organic, all that stuff. the beef is simply superior to really anything you can get. kobe is good too, but much more expensive.
making homemade burgers: for regular beef burgers you can ask your butcher to grind sirloin and many places have the strawberry mountain beef. but if you're just aiming at regular beef you always want to stay away from the "lean" ground beef. lean means less fat and less fat means it will dry out very quickly, particularly when cooking burgers which is usually high heat on a grill or in a pan. i mix beef simply w/ some onions, salt, pepper, garlic and an egg (to bind everything together). do not over mix b/c it will be mushy. this is the basic formula for all homemade burgers when dealing w/ ground meats. turkey for example is extremely lean by nature, so i usually add in some ground pork to give it some fat so it's nice and juicy.
funny story:
my friend who is an ardent WinCo shopper and against all things free-range or organic claims that his cheap ass disgusting beef from WinCo is the best. while it takes a lot to not make a burger good, i disagree with him. cheap beef is nasty all the way around, it's not how cow is supposed to taste.
so i had him and other friends over for a Blazers game and prepared burgers before they got there. but i used the "vegan/vegetarian" fake ground beef stuff, which is not too bad. i made them exactly like above and served them. he and others said it was the best burger they'd ever had. my buddy said, "there's nothing better than ground beef!" while eating it. i informed everyone that they'd been had and no one could believe it.
so it just goes to show you that the cheapest of beef really is tasteless, much like the faux beef. but strawberry mountain or nice ground sirloin...you can certainly tell!