Dom Pérignon is the prestige cuvée Champagne of Moët and Chandon, the largest producer of Champagne by far.
Dom Pérignon IS the most popular prestige cuvée, or top of the line, Champagne worldwide, and is excellent. It's is a mid weight Champagne and known for its elegance, creaminess and superb balance. It's quite dry, shockingly so to neophytes, and has lots of tiny bubbles. Although it's not a blockbuster brute of a Champagne, great vintages do benefit from a few years to mellow and hit their stride. For example, the 1996, although it has drank very well from its release, it still a bit tight in 2000 and will be much better in a few more years.
What is truly amazing is the enormous amount of Dom, nearly a small sea, that's produced with apparently no effect on its quality. Although the exact amount produced is secret, it's probably over a couple million bottles per vintage.
Sometimes mistakenly called Don Perignon, it's named after the monk Dom Pierre Pérignon who supposedly "invented" Champagne by accident. In reality, he didn't "invent" Champagne but "made important contributions to the production and quality of Champagne wine" (source: Wikipedia).
Like most prestige cuvées, it's only produced in exceptional years and contains the grapes from only that one year or vintage. It tends to be excellent every year although the vintage does matter. Each vintage has specific vintage characteristics, as well as varying quality. For example the 1985 blows away the 1992. In fact 1992 and 1993 are weak years that never should have been bottled in my opinion. Sure, they're pretty good Champagne, but not up to standard. They would have been good US$40 bottles, but not $100+ bottles. Relatively recent killer vintages include 1985, 1990, and 1996. Unfortunately Moët and Chandon chose not to bottle the 1996 in magnum, the best bottle size for aging Champagne according to many aficionados. I'm looking forward to trying the 2002 and 2004, not available as of this writing, but reportedly superb years for Champagne.
Dom Pérignon ages extremely well, and bottles from great vintages last many decades. The oldest I ever had was the 1966 in 1996, a thirty year old Champagne, and it was drinking utterly superbly. Others have reported 60 year old bottles, again from the best vintages, to still be alive and vibrant. The taste does evolve and become more complex as it ages, tending towards toast, coffee, mocha, caramel, & nuttiness, and the bubbles diminish as well with age.
There are actually three types of Dom Pérignon. The standard or "Brut" (meaning "very dry") Dom Pérignon, Dom Pérignon Rose, and Dom Pérignon Oenothèque.
The rose has the typical Dom Pérignon characteristics of elegance, balance, and creaminess, as well as red fruits like strawberries and flowers. I like my Dom Pérignon Rose on the younger side, within a few years of release, although many prefer it later, with significant age. I keep an open mind, and the Dom Perignon Rose 1998 was very young tasting in late 2011. The Rose is much more expensive than "regular" Dom Pérignon.
Dom Pérignon Oenothèque is regular old Dom Pérignon that spends additional time in the cellar aging on its lees (dead yeast cells and other solid particles that fall out during fermentation). It spends a minimum of 13 years aging on its lees, as compared to 7 years for the Brut. If you like aged Dom Pérignon, you'll like the Oenothèque, which although it ages somewhat differently on its lees. The Oenothèque is released in limited quantities and is very expensive as well. I love it.
All Dom Pérignon is great, whether the Brut, Rose, or Oenothèque. And when we talk about vintages, well they're all quite good, although if you compare them side by side some outshine others. I'll take a glass or two of Dom Pérignon any day!