In Europe, many single vineyard wines are superior and are bottled as such, but not all vineyards are capable of producing superior wines.

The same thing is true in California (and elsewhere, no doubt). There are a few vineyards that have consistently produced great red and white wines: the original Inglenook and Beaulieu vineyards, Martha's vineyard which Heitz did so well with, the Stags Leap vineyard Warren Winarski uses, Cathy Corison's Kronos vineyard (all in Napa Valley), the Ridge Montebello vineyard on the Peninsula.

In many cases, however, in California, one can make superior wines by blending lots of grapes from blocs different vineyards.

So, just because a wine is a single vineyard designate, does not mean it's a superior wine.

Depends on the vineyard.

I enjoy tasting single vineyard wines side by side when I'm out tasting to get a sense of terroir. However, RPM (as usual) is very correct in saying that most wines are best when blended.
In California, I tend to recognize AVA's more so than individual vineyards. One has a pretty good idea of what to expect when opening a Rutherford Cab or Rockpile Zin, for example.

Yes, I agree with RPM. The recent movement to push for single vineyard wines seemingly everywhere, seems like just a way to push prices up by driving up scarcity and not necessarily increasing the quality.

agreed, but I will say that I really enjoy a horizontal (is that the term?) tasting of different vineyards of the same varietal made by the same winemaker from the same year.