The fact is it's neither hard nor expensive to add a reasonable selection of Spanish Wines to add interest and variety to your cellar. Probably the best advice is to keep it simple, but varied.

A good place to start might be a bottle or two of:

Rioja: Crianzas & Reservas [Red]
Penedés: Crianzas & Reservas [Red & White]
Ribera del Duero: Crianzas & Reservas [Red]
Rueda: [White]
Rias Baixas: "Albariño" [White]
Jerez: Finos & Amontillados
Cava: Brut & Seco

Here at Bacchus Vintners we very much favor the reds, and the Crianzas and Reservas tend to be quite good, and reasonably priced. Depending upon your personal taste (and of course budget), there's a lot to choose from in both cheaper everyday wines, and in the more expensive Reservas and Gran Reservas.