Two examples of where AppleCare would have helped me, both occurring in year 2 of Macbook Pro ownership:
- Blown power management circuit, requiring logic board replacement. Non-Apple care cost: $600
- Intermittent ethernet port on MBP #2, again requiring logic board replacement. Non-Apple care cost: $600
On the first MBP, I decided to simply buy a replacement base MBP and move over my SSD and RAM, since I also got a fresh battery and another year of warranty at what ended up being a good price overall compared to repair.
On the second one, now that I've got a bum ethernet port, I've decided to simply live with wifi and using a USB ethernet wired adapter when required.
Edit: And stupidly, I didn't buy AppleCare on that second one

Although, truth be told, I'd just as soon replace it with an Air at some point down the road anyways, so I'm not overly concerned if it dies with no warranty.