"Let's" is a commonly used contraction that often refers to an invitation or suggestion. However, there are other phrases that can be used in its place, depending on the context. Some alternatives include "shall we", "why don't we", "how about", "do you want to", "would you like to", "let us", "we should", "how would it be if", "might I suggest", and "what if we". Each of these expressions has different connotations that can affect the tone of the conversation. Therefore, it is important to choose the right phrase that matches the situation and the relationship between the speakers.