Are these so-called 'light' beers actually lower in calories than normal beers? what is the best low-cal beer to drink?

They're low calorie because they are mostly watered down beer. I'd have to be very thirsty to drink a Lite beer.

Lite beers are indeed lower in calories, they are initialy made from less fermentable products than a higher gravity beer. If I had to choose a lite beer to drink, it would be Sam Adams Lite. They do an excellent job with all thier products.

They are lower in calories and lower in carbohydrates. The best low calorie beer I have had is Michelob Ultra and Michelob Ultra Amber. Everyones tastes are different though.

Beer is more fattening than wine or liquor; lite beer is less fattening than wine (red or white but more fattening than liquor:
Beer (reg) 153 calories 13 g. carb. 0.00 fat
Beer (lite) 103 calories 6 g. carb 0.00 fat
80 proof liquor ( vodka, gin, tequila, whiskey, rum
97 calories 0 g. carb 0.00 fat
Wine (red)125 calories 4 g. carb 0.00 fat
Wine (white)121 calories 4 g. carb 0.00
Which is the best tasting light beer is a matter of taste.
http://www2.potsdam.edu/hansondj/HealthIssues/1083349678.html