beverage suggestions

Iced tea. Use flavored tea bags. I like using 1 family sized bag and 2 (individual) flavored ones for 1/2 gallon. Lipton Pyramid Bavarian Berry (black tea) or Lipton Superfruit Red Raspberry (green tea) gives the "plain" tea just enough flavor to make it much smoother. I don't need sugar.

Re: green tea. Do not brew with super hot (boiling) water, or it will be bitter.

If black or green tea isn't your thing, try using herbal teas. I used Mixed Berry herbal (Twinings) with black tea bags.....nice and mellow.

Rooibos is a red tea, very mellow almost sweet. Celestial Seasonings makes a nice vanilla one.

Water?

Something with natural flavouring only, like lemon/lime/grapefruit Perrier?

Are you only avoiding sugar because MFP told you to, or do you have a medical reason? If it's the former and soda still fits into your calories for the day, it's not really worth worrying about as it's just an autogenerated target. A moderate amount of sugar is fine for healthy people if you're getting adequate nutrition (macronutrient balance and the necessary vitamins and minerals) from the rest of your food.

I would suggest cutting out soda for everyone, for a variety of reasons, but who am I to talk with my daily chocolate fix! Haha!

I usually cut a lemon in half and squeeze it into a glass and add a can of sparkling water (12 oz, maybe?) when I'm having a craving. My craving is for the citrus drinks like Mt. Dew or Squirt, so this helps me and gives me the acid/carbonation satisfaction with minimal calories or sugar.