Well, one thing is a certainty.

I agree with using half crystal light too. I love diet ocean spray juices (5 calories) but they are strong so I dilute with water and ice

Can't take the sickly sweet either.  It made it tough for me to find a protein mix.

My faves are Peach Passion tea, True Lime and stevia mixed in ice water to taste, and diluted juices.  You can dilute them yourself, but I like Motts for Tots and Trop 50.  I mostly used the apple when I was very early out from surgery.  The orange I mix w/water and my vanilla protein powder.

Plain unsweetened tea, I don't know how anyone tolerates sweetened drinks they are gross to me and I LOVE me some sweet treats, just not drinks.  I drink unsweetened iced tea with lemon all day, I am sure a little lemon juice would be okay, check with your dr.

Finally found something I can tolerate! Ocean Spray DIET BLUEBERRY! Love it. I have some other Ocean Spray drinks that I've not opened yet. I'm very happy with this one for now though.

I've been drinking a lot of Propel, both the pre-bottled and the packets mixed with water.  It's got a much milder/less sweet taste than Crystal Light.  It does have Splenda, but it's not nearly as strong or sweet.

Another one I like is Lime Margarita drink mix from Target.  It's tart, not sweet.