Informal:
* वाह! (Vāḥ!) - This is the most common and versatile way to express "wow" in Hindi. It can be used in a variety of situations, from expressing surprise to admiration.
* अरे वाह! (Are vāḥ!) - This is another informal way to say "wow", often used with a bit more emphasis.
* वाह क्या बात है! (Vāḥ kyā bāt hai!) - This means "wow, what a thing!" and can be used to express amazement at something impressive.
Formal:
* अद्भुत! (Adbhut!) - This means "amazing" or "wonderful" and is a more formal way to express "wow".
* शानदार! (Shāndār!) - This means "splendid" or "brilliant" and is also a formal way to express "wow".
The best way to choose the right phrase depends on the situation and who you're talking to.