"On top of the heap" is an idiom that is often used to describe someone or something that is highly successful or respected. However, there are several synonyms that can also be used in place of this phrase. One common synonym is "at the pinnacle", which suggests reaching the highest point of success or achievement. Another synonym is "ahead of the pack", which implies being in the lead position compared to others. "Topping the charts" is also a suitable synonym, often used in reference to music or entertainment. Overall, there are many ways to describe being at the top of one's game, each with their unique implications.