Becky bought her first Mac and it's been in and out of genius bar with repairs. It keeps dying and she's worried because her Apple Care is about to run out. It could be that her power is fluctuating causing components to fail. In that case, she can get a UPS from TrippLite that will condition her power. She would want to find one that is constantly conditioning the power, and those cost a little bit more.
Leo ultimately suggests telling the Apple Store that she needs the computer replaced. She tried that, but Apple says that is not an option. Leo says it's clearly a Lemon and the under federal law, multiple repairs means she has a lemon and Apple should replace it.
She should write politely to Tim Cook, mentioning that this is her first Mac. Apple has a team that deals with things like this. It won't hurt to mention that she talked to Leo Laporte on the Tech Guy Show. Quote the Song Beverly Consumer Warranty Act and the Magnus and Moss Warranty Act. Both cover all consumer goods to be either replaced or refunded in this issue. Document everything showing the repair trail. At which point, they'll have to do the right thing and replace it or refund her money.
The address for Tim Cook at Apple is:
1 Infinite Loop
Cupertino, CA 95014
Tim's email is email@example.com.