Formal:
* Quelle surprise! (pronounced "kel soo-priz") - This is the most direct and common translation, meaning "What a surprise!"
* C'est une surprise! (pronounced "sayt oon soo-priz") - This means "It's a surprise!" and is more formal than "Quelle surprise!".
Informal:
* Waouh, quelle surprise! (pronounced "wow, kel soo-priz") - This is a more enthusiastic and colloquial way to say "What a surprise!"
* Oh là là, quelle surprise! (pronounced "oh la la, kel soo-priz") - This is another exclamation of surprise, often used with a touch of disbelief.
Other options:
* Quelle agréable surprise! (pronounced "kel ah-grah-dah-bl soo-priz") - This means "What a pleasant surprise!"
* Quelle drôle de surprise! (pronounced "kel drol de soo-priz") - This means "What a strange surprise!"
The best way to choose the right phrase depends on the situation and your relationship with the person you are talking to.