Spain's best-known wine region is Rioja. A relatively small area nestled between two mountain ranges in north central Spain, Rioja produces extraordinary red wines that won't break the bank. The primary grape in Rioja is Tempranillo which is often blended with Carignane and Grenache. A good Rioja should have dark, plumy fruit with lots of spice and tannin. Riojas with the labeling of "Crianza" or "Riserva" have been aged for a minimum of two years with at least six months in oak, a process which will round out adolescent fruit and makes the wine more approachable. Saturday night we poured the 2003 Artadi Vinas de Gain ($27.99) from Tribeca Wine Merchants (40 Hudson Street between Duane and Reade) for a group of fourteen friends. This red was the perfect complement to a filet roast with it's rich, deep, violet and plum fruit that left everyone raving. Astor Wines (12 Astor Place) offers an extensive selection of Riojas. Another fine example of a beautiful Rioja, the 1997 Vina Izadi Reserva, is a steal at $21.99.