There's not much I realistically want now. Most things when you start to really think about them require a lot of work to maintain- relationships, careers, achievements. Even money won't stop illness or age. Realistically, I want the end of all desires- death. I'd like the time and money to go and visit a few places. Nothing really lavish- I'm quite happy to stay in the UK and then, to peacefully slip away.
If we're talking about the Mirror of Erised in Harry Potter though- my reflection would be similar to his- full of dead family members standing around me. That scene always makes me cry.