An expression used when something is good in a satisfying way. Similar to 'cool beans' but more commonly used within a sentence as opposed to as being an individual phrase.
The game last night almost made me cry it was so good. The melted cheese of all games!
Have you seen that guy's shirt?
Melted cheese.
When you are not doing anything but waiting for friends to join you.
I was melting my cheese in the living room hoping Jade would not be late.