I love the diet Dr Pete -- tastes like diet Dr Pepper. Also like the Cola sugar free (in the black bottle). Just make sure you don't use too much syrup! (DON'T fill the cap all the way to the top -- it will taste like burnt sugar.) Use the measuring lines etched into the inside of the cap. If you can't see them, just run your finger inside the cap and you'll feel them there. There are three lines -- bottom line is for 250ml, second line is for 500ml, and top line is for 1 Litre. The top line is about 3/4 of the way up the cap. If you get the right amount of syrup it will taste just right.