Signature restaurant

[JPablo]

I understand "signature" as, –adj. 11. serving to identify or distinguish a person, group, etc.: a signature tune.
(as a noun, 5. any unique, distinguishing aspect, feature, or mark.)

I would go with "restaurante distinguido" or "restaurante con solera única" or something like that.

Does anyone have a shorter Spanish version, or a better idea... or a more used one?

[ookami]

For me your first one is the best choice and one of the most used ones. If you want to use another adjetive, I will go with destacable, famoso, ilustre and célebre (maybe in that order). The words "conocido"(well-known) and "restaurante" are usually together too. But conocido isn't exactly distinguido.

[JPablo]

Thank you Ookami. Your views help. Even, "de conocida fama" or "de prestigio" would be good options, now that you gave me more inspiration.

[Rusty]

¿Qué te parece un restaurante destacado?

[JPablo]

Me parece una buena idea, Rusty. Coincide con la de "serving to identify or distinguish a person, group, etc." y le añade 'notoriedad'.
¡Gracias!