Coke.

Coke.

Well if that's the propaganda you choose to believe then I'll respect your choice.

Always Coke =)

 Do you have any proof of this? I have done a bit of research on the area, and Aspartam (the main sweetner in Coke zero and Pepsi Max. Some countries still have sucralose as the main sweetner in Diet Pepsi/Coke light, but most have aspartam there as well) is one of the most tested artifical sweetners through all time. It was banned for a long time, from its discovery in the late 60s to sometime in the 90s been allowed in pretty much all countries (been over a year since I checked this... dates could be wrong).

And several companies testing this have said that as long as you drink less than 4.5 litres of coke a day, in addition to the average consumption of aspartam, you'll be completely safe. This doesn't mean that if you drink above 4.5 litres a day you're in danger, but it's not yet certain that it's safe.

The other sweetner acesfultam has also been tested thorougly, and it is viewed as almost completely safe. Just by drinking coke, you'll die of over-drinking before this. It has a certain addiction to it though, that makes you want more sugar/acesfultam/aspartam/sucralose, but as aspartam is as strong as it is, this isn't the same issue as it was with sucralose (which was the main sweetner between 2002 and 2007, at least in Norway).

Acesfultam may also cause you to burn calories and such at a lower pace, but this is (as of last year) not confirmed to be true nor false.

And on topic.

I've actually done a test of this. My family and 2 other families did a huge test during the 06/07 christmas. 10 versions of coke. Of course, it was all diet cokes. 

Surprisingly enough, coke and pepsi didn't win.

Freeway coke finished first for most people - to their own huge surprises. It costs ~ 50% of the discount price for coke and pepsi (when you buy in 4, 6 or 10 packages of 1.5 litres).

Personally, I'm a fan of Tab-Xtra.

Of the major ones, it's

Tab-Xtra > Coke Zero > Pepsi Max > Coke light > Diet Pepsi.

Neither, Dr. Pepper

They taste 95% the same so I don't care. Coke has a better looking can though so I will drink that if I have a choice.

Pepsi

Pepsi

I don't drink soda that much. If you have to ask, I would say Pepsi because it has a sweeter taste than Coca Cola.