I was just about to put Gatorade... but I wasn't sure if it was offered outside of the US (and I wanted to keep it general).... then I almost put the generic "sports drink" - but decided... Naaa.... already have plenty of options.
As a side note, I also hate drinking just plain water (unless I'm really thirsty) - but I drink it all the time now because I love a lot of the different additives you can add to the bottle water (like lemonade, Gatorade, etc....) My favorite is the Wal-Mart generic brand that turns the water into Apple flavor water.
Anyway.... don't drink as much Mountain Dew anymore..... and will drink 1-3 bottles of water a day now (with added flavor)