I personally like the Spanish wines from the Rioja region. The white wine quenches my thirst like a fresh glass of water. It was amazing.
Here is a succinct synopsis that will give you leads to Google. Personally, it is the 'brightness' or acidity if you will that makes Champagne so great and if you want to experiment try finding 'sekt' or 'trocken' when searching - meaning dry in German, the drier the better. German wines are notorious for bright and acidic wines both sparkling and non-sparkling. American sparklings produce some great flavors like what Domaine Chandon (Napa) produces but just don't have the sharpness to justify the price point.
You shouldn't have any trouble finding some quality "Cava" either at really good prices. Many don't realize that Spain actually possesses the most vineyards in the world.