whats the difference between Coke Zero and Diet Coke?

Diet Coke is sweetened with aspartame, and Coke Zero is sweetened with Splenda.

Coke Zero actually tastes like Coca Cola while Diet Coke just tastes bad.

I think it's that Diet Coke has aspartame, while Coke Zero has Splenda. Either one will or will not give you brain cancer (depending on the source), but I prefer Coke Zero over Diet Coke - personal preference.

Diet Coke has selected sweeteners including asparatame (which btw if use drink things with this in it for a long period of time, it can cause tumours) and Coke Zero has no sugars or sweeteners which is so boring and ps i think it tastes nasty!

i always thought coke zero had no sugar in it and diet coke had no caffeine or vice versa

They have different sweetener additives

Great question.....

try

http://en.wikipedia.org/wiki/Diet_coke

and

http://en.wikipedia.org/wiki/Coke_zero