AND SO: Your burgers aren't delicious and might not even be made of cow.
First, remember that once meat is no longer a cow, every step of processing and packaging introduces an additional chance of contamination. And let's be honest — especially in the case of shrink-wrapped, pre-pattied ground beef, there could be anything in there.
Sketchy, cheap ground beef won't necessarily make you sick. But when I have to buy and cook it (and we all find ourselves in that position, especially in rented summer houses in remote towns with tiny grocery stores), I cook burgers to medium to make sure to kill anything nasty. And that makes for a less delicious burger.
So get the best meat available that you can afford. That means ground chuck — and remember that the perfect ratio is 80% lean and 20% fat. Fat is important. And if you can, ask the person at the butcher counter to grind it fresh while you wait. That will make a huge difference.