You see them everywhere -- in restaurants, wine shops, gift catalogs and websites -- fancy wine glasses costing anywhere from $10 to over $80 per stem, and you wonder, "Does the type of glass I drink my wine from make a difference?" The answer is, conditionally, yes it does.
It's conditional because any vessel light enough to be lifted and possessing only one hole (the one in the top), is capable of conveying the wine from the table to your lips, presuming you have an opposable thumb and can bend your elbow. If that's all you're concerned with, then there is not much point in dirtying a glass at all -- might as well just take a couple belts right from the bottle.
Once you've decided to conduct yourself with a modicum of civility, it's good to think for a moment about the purpose of drinking a glass of wine: it is for enjoyment, for pleasure. That being the case, the glass should add to the fun, not detract from it. Wine's delights are conveyed primarily through three of your five senses, those of sight, smell, and taste, so the glass should facilitate, preferably even accentuate the wine's ability to gratify those senses.
There is an Austrian company that has been making a concentrated study of this very issue for more than eleven generations. For the last three, Riedel has even made specific glasses for specific wines, such as Cabernet Sauvignon, Pinot Noir or Chardonnay. Their high-end glasses are hand-blown Austrian crystal custom designed to illuminate the characteristics of the particular grape, or in some cases, a particular region like Bordeaux or Chianti. They also do glasses for beers, particular liquors like scotch, grappa and tequila, and even a water glass. Each design is carefully and repeatedly tested by experts around the world until the shape and size that best focuses a particular wine's individuality is achieved.
It works, too. Taste a wine in an ordinary glass such as you'd buy in a discount store, then try the very same wine from the same bottle in a Riedel stem made for the purpose. The smells leap out of the glass, the flavors dance across your palate, even still wines sparkle.
There are many considerations that go into the production of each design, but one of the simplest to understand is the lip. Commercially available tempered glass will often have a rim that is reinforced by a bead of thicker glass right at the rim. This is designed to prevent chipping. Unfortunately, this also has the effect, as you take a drink from these glasses, of directing the wine straight to the back of your mouth, skipping most of your palate entirely. Riedel rims are thinner, and as a result, the wine immediately flows to all corners of your mouth, allowing the harmony of flavors (or, yes, lack thereof) to reveal itself. It is true that while good wines are made better, some bad wines are made worse by having their flaws more thoroughly exposed.
Not long ago Riedel made quite a splash with a new series of glasses, identical to their others but for the lack of a stem -- they are essentially tumblers. They still possess the magic of the more formal glasses, but I've found that without the stems the glass gets smudged with fingerprints quickly, and that spoils the fun for your sense of sight. Hovever if you are not quite as nitpicky as I, then these are a fun, casual way to enjoy the benefits of Riedel engineering.
Oh, and that nonsense you may have heard that holding a wine glass by the bowl as opposed to the stem will raise the temperature is just that - nonsense. I tested it, and after 20 minutes of cupping the bowl with my hand the wine went up less than one degree, hardly enough to be noticed.