I remember Coke seemingly tasting better when I was a kid. Up until fairly recently, I figured it was just the glass bottles. Then I discovered that since around 1984 or so, they've been making it with corn syrup instead of sugar, which many people on the internets (always believe everything you read on the internets) swear is a million times better.
So, last week I was in Winn Dixie and saw some Coke which was advertised as kosher for Passover. Not knowing what the hell would make Coke kosher or not, I looked it up on the aformentioned internets and apparently the Passover Coke is sweetened with sucrose, instead of corn syrup. So it's supposed to be more like the good stuff, though still not as good as Mexican Coke, which uses cane sugar (again according to the internets). So I bought some (it has a yellow cap), and I'll see how it tastes when I get home. If it really does taste better, then I'm going to be pretty pissed at Coke for using corn syrup all this time.
UPDATE: The verdict is in. Not much difference. If anything, it's slightly worse, flatter. Unless I got a bad batch or something, I'm unimpressed. Still look forward to trying the Mexican Coke with real sugar sometime.