Formal:
* Votre perte: This is the most literal translation and is appropriate in formal situations.
* C'est votre perte: This means "it's your loss" and is more direct.
Informal:
* Dommage pour toi: This means "too bad for you" and is more casual.
* T'as raté quelque chose: This means "you missed something" and is even more informal.
More specific:
* C'est dommage que vous ayez raté...: This means "it's a shame that you missed..." and allows you to specify what you're referring to.
The best way to choose the right phrase depends on the context of the conversation and your relationship with the person you're talking to.