Formal:
* Espero poder verte pronto. (This is the most literal translation and is suitable for formal situations.)
Informal:
* Espero verte pronto. (This is a common and casual way to say it.)
* Ojalá te vea pronto. (This translates to "Hopefully I'll see you soon" and conveys a stronger desire.)
* ¡Espero verte pronto! (Adding an exclamation point makes it more enthusiastic.)
More affectionate:
* Tengo muchas ganas de verte pronto. (This means "I'm really looking forward to seeing you soon.")
The best option will depend on the context and your relationship with the person.