What is less known is that Portugal has a large variety of great wines cultivated in a various regions. My favourite region for Portugese wines is Alentejo, a region south of Lisbon with a very dry climate which enables to make great wines. It's popularity in Portugal is huge, and wines from the region represent 44% of the market. Especially the red wines which are fully bodied and often oak aged remind of the world wines of Argentina and South Afrika. The majorty of wines of this region use local grapes such as Arregones and trincadeiro, sometimes combined with French varieties such as cabernet sauvignon or merlot. Famous brands are Esporão, Borba, Montsaraz.... If you are in a Portugese restaurant and need to choose among multiple wines, just choose a wine of the Alentejo region and you are almost always on the "safe"side. Off course, price and quality are also here linked to each other, and good wines in a restaurant start from EUR 10-15 up to 25-30 and more...
Regarding white wines, the typical wine in Portugal is the "Vino Verde", a light and slightly sparkling white wine. I'm not particularly a big fan of these but when it's hot in the summer they are fresh and tasty, especially in combination with typical sardines roasted on the barbecue.
Another famous wine who many people might know is "Mateus", the sparkling sweet rosé with a special bottle, which you can find in almost any supermarket. According to a portugese friend of us, Portugese tend to export it, keeping their best wines for themselves...;-)