In 2004, the American super-critic, Robert Parker, predicted that Spain would emerge as a leader in wine. He spoke both of better quality and also greater creativity. He was not far wrong.

When he predicted that traditional wine regions like Rioja would play second fiddle to up-and-coming areas – Toro, Jumilla and Priorat in particular – his crystal ball clouded over. The fact is, Rioja has more than kept pace with changing tastes. It has embraced it, in fact, becoming Spain's most diverse wine region, with a broad mix of styles ranging from traditional to modern, from oaked to unoaked, from commercial to great, from blends to single vineyard wines – and, importantly, from fine reds to excellent whites.

How has it managed the transition? Broadly speaking, Rioja's producers have learnt how to prosper in a world made increasingly competitive by good-value, fruit-driven New World wines.

In the vineyard, more attention has been paid to bringing in healthy, ripe grapes in smaller amounts, while also exploiting old vines and seeking out the best terroirs.

Fruitier wine styles continue to proliferate, too. Makers cutting down on vessel size, oak levels and ageing times and where oak is used, upping the French oak component at the expense of coarser American varieties.

It's easy to get tripped up by indifferent, cheap wines in Rioja. But, that said, at the same time there are surprises to be found in the foothills of Rioja, like the spicy, strawberryish 2008 Baron de las Viñas Rioja Reserva, £10, Sainsbury's; the polished, modern 2012 Perez Burton Rioja, £11, Marks & Spencer and spicy, rich 2008 Bodegas Muriel, Reserva, £7.49-£12.99, Corkers, Laithwaites. For fans of traditional oak styles there's a 2008 Asda Extra Special Marques del Norte Rioja Reserva, £6, along with the supermarket's impressive 2004 Asda Extra Special El Mesón Rioja Gran Reserva, £12.98, and, also with that same mature edge: the 2007 Tesco Finest Viña Mara Rioja Gran Reserva, £11.49.

If you're prepared to pay a little more, in the £15-£30 range, you will find Rioja which excels: such as Finca Allende, Roda, Remelluri, Ramirez de Ganuza, Artadi and those that straddle the modern/classic divide such as Muga, La Rioja Alta, Luis Cañas, Martinez Bujanda, Marqués de Murrieta and CVNE.

Among my current favourites are the 2009 Marqués de Murrieta Reserva, £17.50, The French Wine People, and La Rioja Alta's succulently smooth, but not a little gamey 2005 Viña Arana Reserva, £17-£21.95, Wine Society, Cambridge Wine, Berry Bros, and both CVNE's delicious 2008 Rioja Reserva Imperial, £15, Asda, and complex, leather- and damson-infused 2007 Rioja Gran Reserva, £28.95-£29.99, Eton Vintners, Waitrose.