coke zero
aspartame isn't that bad for you, you'd have to drink around 20 cans a day for any even remotely ill effects (mild headaches etc) , it's just made of two amino acids ( L-phenylalanine and L-aspartate )both of which are found in all proteins.
people who are worried about the ill effects of a can of diet soft drink or two must live in a hermetically sealed bubble of health cos your more likely to get ill from walking down the street.
Although aspartame is addictive. About 5 years ago i got too a stage where its all i could drink, a substitute for water more or less. I would say I was dringking about between 1 and 2 ltrs a day. Made me really ill all the time, constant headaches, insomnia and generally didn't feel to great psycologically. Put on about 3 stone for no apparent reason. I know mainstream science will tell you its perfectly safe but I just go on personal experience.
I eventually managed to cut it out and all 'sugar free' products and for the past three years I have been as fit of a fiddle, no headaches, no colds, no nothing to be frank. My weight returned to normal. I made no other changes to my lifestyle so I put it down to aspartame and research into it has more or less cemented that opinion. Like many additives, its a toxic substance under the right conditions, like flouride in your toothpaste and water, mercury in your fillings etc. Your better off without them in your body.