Wine Regions in Spain
Why not try Catalunya: fly into Barcelona, head west and discover some Catalunya wine regions - take in first Penedès but skip the obvious Freixenet/Codorniu options in favour of classy cava producers like Recaredo in Sant Sadurni, for biodynamically raised, old-vine, long-aged sparklers. And don't overlook still wine producers, esp. in Alt Penedès, like Mas Rodó. Also while in Penedès, a must is Restaurant U in Les Gunyoles for Raimón Olivellas' amazing food and terrific wine list with lots of ideas for your research. Then move over west to Conca de Barberà (Clos de Montblanc does good work and Milmanda (Torres) is located here too, where you can taste by appointment), and thence to Priorat/Montsant where there are rich pickings. Priorat is in MHO overhyped/priced but Montsant has loads to offer, mainly from old-vine Garnatxa/Carinena vines with some input from int. varieties - Capafons Osso in Falset, Orto Vins in El Masroig (wine is made in El Molar), Coco y Fitó also based in El Masroig and Vinyes Doménech were all recent recs by the ever-resourceful, locally-based Rachel Ritchie, www.rachelritchie.com cited on other threads on this board. Be sure to eat at El Celler de l'Aspic where chef-owner-sommelier Toni Bru does wonders with both food and wine list. Then, if time (you could do this all in a week, I just did it), move west again and poke your nose into Terra Alta - good names include Barbarà Forés and Celler Piñols, interesting barrique Garnatxa Blanca, but fine reds too.
Have fun, and please report!
I plan wine trips as a profession, so I have plenty of experience trying to do this in a week. I do think Rioja is a MUST. There are a wide range of bodegas from old school (Muga and Tondonia) to quite progressive ones with amazing architecture (such as Baigorri and Finca Valpiedra). The scenery is spectacular, restaurants are amazing, and towns like Laguardia are what we call "impossibly charming." There are a range of hotels too from quite reasonable properties to unique four- and five-star properties. Folks here speak less English than in most parts of Spain. A lot of people don't know that the best bodegas are located in Alava, which actually is a Basque province. Riojan cuisine is AMAZING. Now the question is what to pair that with. Frankly I would not pair Rioja with Ribera del Duero. Yes, the wines are great..not denying that, BUT it's not terribly pretty and the infrastructure for visitors is just not there yet. I find it boring. There are a couple of options if you really want to be aggressive. One is to fly to Barcelona which you can do from Bilbao VERY inexpensively on Spanair. A simply amazing wine region is Priorat - 2 hours sw of BCN. It is pristine, incredibly beautiful (very steep vineyards where everything must be done by hand). It is much, much smaller than La Rioja and some incredible wines are being produced there (primarily Rhone and Bordeaux varietals). It is a very, very nice contrast to Rioja in my view. Of course, a great week is to do San Sebastian + La Rioja. While this only gives you one major wine region, San Sebastian is great - a world-class food town. You can visit Txakoli bodegas in the incredibly beautiful green coastal mountains just 30 mins from San Sebasitan. These all are family-run and you can't just wander in. Penedes just 45 min outside Barcelona is not worth the journey. It's nice, but not comparable in my view to Priorat although we love Pares Balta!! If you really are 100% committed to a week of wine, I would pair La Rioja (fly into Bilbao) and Priorat and spend a night or two in Barcelona. That's my take. Enjoy.
The "Rioja" region may be the obvious choice but that doesn't mean it is bad, lots of very interesting cellar doors well set up for wine tourism. I would then head down to the "Ribera Del Duero" region and if you have time to "Rueda" (good whites). For me three regions in a week would be hard work but as these three are next to each other worth a shot - especially if you want to see variety. Either start at the top and fly into Bilbao for Rioja and then fly out of Madrid after Rueda or reverse the route. It is a good days drive between Madrid and Bilbao if you need to go in and out from the same place.
Spain has quite a few other very good wine regions but they are more spread out and are not in such close proximity to one another.