Marques de Caceres
This is one of my favorite Spanish producers. Try their (red) Rioja Crianza or Reserva--very approachable, with lots of fresh cherry fruit and just enough structure and tannin.
Incidentally, Marques de Caceres switched over to screw caps for their whites for the 2004 vintage. Their Rioja White 2004 is 100% Viura, the most popular white grape in that region. It was done in all stainless steel, and the result is a vibrant, fruity, crisp white that goes well with food and is perfect for patio sipping this summer.
There are a lot of exciting things going on in Spain, wine-wise. Check out The New Spain for a primer.