Here are some other options, depending on the context and formality:
* "Até logo" (See you later) - slightly more formal
* "Até mais" (See you soon) - more casual
* "Adeus" (Goodbye) - very formal, used in farewells
* "Até breve" (See you soon) - a bit more formal than "Até mais"
The choice of which to use depends on the situation. "Tchau" is the most versatile and can be used in most situations.