at the top of the heap —(also: at the top of the tree)
1. as high as possible in one’s career or profession:
- Regardless of who is at the top of the heap in our government we are still the most diverse nation.
2. of the highest rank within a group of items:
- At the top of the heap are private colleges and universities such as Yale, Williams and Harvard which are world re nowned.
on top of the world—extremely happy:
- I was on top of the world and it seemed like just the beginning of a long and glorious career.