Personally, I find Belgian Ales to be of the finest in the world. There are so many that I would like to post here. From the Trappist Abbey ales, to farmhouse brews, Saisons & Lambics. There are just so many.
In any case, here are a few to start off. All of which should be tried at least once before you die......
For more info on Belgian Ales, check the link in my profile.
Chimay Grand Réserve
Origin: Province of Hainaut, Belgium
Style: Abbey (Authentic Trappist)
Alcohol: 9.0% ABV
The most port-like of the Trappist Ales is the vintage dated Grand Réserve. It is the strongest of the three principle brews made by the Trappist monastery of Notre-Dame, at Scourmont, near the town of Chimay, in the far south of Belgium. The port flavors develop if the beer is laid down for 5 years or more. This aromatic, lively, rich ale has a sweet middle, with drier suggestions of thyme, pepper, sandalwood, and nutmeg in the finish. It is a complex classic, great with some Chimay cheese.
Huyghe Delirium Tremens
Origin: Province of East Flanders, Belgium
Style: Strong Golden Ale
Alcohol: 9.0% ABV
Flippant names such as Delirium Tremens reflect the Belgian spirit of "eat, drink, and be merry". The name once resulted in the beer being banned from the United States. For the American market, it was given the name Mateen, after an early Flemish brewer. The beer employs Saaz & Styrian hops, and is fermented with three yeasts (in a 2-stage fermentation and bottle-conditioning). It has a very fruity aroma, reminiscent of plums or gooseberries; a sweetish palate; and a lot of warming alcohol in the finish. 
Saison Dupont
Origin: Province of Hainaut, Belgium
Style: Saison
Alcohol: 6.5% ABV
Probably the best known Saison. In the French-speaking part of Belgium, the word "season" sometimes appears on beer labels. The season in question is always summer. As the Belgians like strong beers, even their summer brews are often potent. They are firm and dry, with a yeasty, fruity acidity like that of an orange, and usually unfiltered. Saison Dupont is a classic. It is made at the farmhouse brewery at Tourpes, near Leuze, east of the town of Tournai. The brewery makes several variations on this theme, some labeled "Moinette", the name of the farm (In French, moine means monk, and the farm is on what is believed to have been an Abbey Estate). The farm also makes breads (some using grain from the brewery) and a range of cheeses (one spiced with finely chopped hops).
Rodenbach Grand Cru
Origin: Province of West Flanders, Belgium
Style: Flemish Red Ale
Alcohol: 6.0% ABV
While the regular version of this famous Flemish Red Ale is a blend of old and young beers, the Grand Cru is a straight bottling of the long-matured, stronger component. It is aged in ceiling-high oak tuns for at least two years. The result is a lively boquet, with vanilla-like oakiness that extends into the palate; passion fruit flavors; and a clean, sharp acidity like that found in sour cream. Rodenbach Grand Cru would feature on any connoisseur's list of the world's top ten beers. Excellent.
Never tried the brune, I 'll have to put that on my list.
When British beers were fashionable in Belgium, the family owned Moortgat brewery, at Breendonk, north of Brussels, produced a Scottish Ale, using McEwan's yeast. The brewery later decided to restyle it, keeping the yeast and ale fermentation, and the high strength, but using pale malts. The beer is hopped with Styrian Goldings and Saaz. A series of warm & cold fermentation and maturation lasts for over three months. "A devil of a beer", someone in the brewery observed of the first batch, hence the Flemish 
is actually a Witbier (white beer). A Witbier is a pale golden, tart, refreshing style; thick with sediment and with a high level of carbon dioxide. With the pale malts, unmalted wheat and lack of filtration, it bares some resemblance to German HefeWiesse. The greatest different between Wit and its German cousin is the addition of spices, typically coriander and bitter Curacao orange peel.
