The milkshakes from Burger King are pretty good. My mother-in-law prefers vanilla, but chocolate is my pick. Yesterday, I had one of their chocolate milkshakes and really enjoyed it.
I don't know the nutritional value because there is no info about this on the large cup that the milkshake comes in, but I'm sure that these milkshakes are loaded with sugar and calories. The flavor is very good, and the size I had was about 16 ounces. I have noticed one difference between some of today's milkshakes as compared to milkshakes I used to indulge in years ago. A lot of today's milkshakes are more watered down. Years back, when I used to get a milkshake, it would be so thick you could just about get it through your straw. Nowadays, that doesn't seem to be a problem. It doesn't really bother me, though, because I actually like being able to get the liquid through the straw more easily, but sometimes I do miss the thickness of the milkshakes the way they used to be.
Despite that, Burger King's chocolate milkshakes are tasty, with a good chocolatey flavor. And a big 16 ounce cup is definitely enough to satisfy the cravings of any chocoholic.
Update On Oct 06, 2009: I just wanted to clarify something in my review. I mentioned that today's milkshakes some to be more watered down. The Burger King milkshake I had previously was somewhat runny. I had another one just the other day, and it was very thick. My mother-in-law has informed me that all of the vanilla milkshakes she's had were also thick. I think that the one I had previously was more watery because I didn't drink it immediately. I just wanted to clarify that point, Burger King Milkshakes are thick.