I like drinking water, room temp is preferable, especially when its hot. My preference is coffee.
I haven't had a soda (we call it "pop" here in OR) in probably 5 years. Cutting out all that sugar was the first major step in my weight loss which is right at 100lbs of fat lost so far. I've gained quite a bit of mass from muscle gain, probably 15-20lbs or more. Total lifestyle change. Getting rid of the major sugar sources is paramount to that change.
The other thing I highly recommend is eating lots of greek yogurt and I also take probiotic gummy bear things. Getting the bacteria in your gut correct is the other major key. I read something once upon a time where a gastroenterologist said that there are basically 4 types of guts, depending on which of the bacteria is dominant. One is very conducive to a thin person, and another is very conducive to an obese person, IIRC.
just my .02.
PS - don't ditch the sugared soda for the sugar-free shit, either. I personally believe that the artificial sweetener fucks up your insulin system, because your tongue tells your brain "HOLY FUCKING SHIT, TONS OF SUGAR INCOMING!!!", and your brain does its thing and dumps insulin into your blood stream thinking there is some type of a sugar available... but there isn't. Repeat this over and over and over, and your whole system goes batshit crazy and BOOM.... type 2 diabetes, motherfucker.
Avoid that shit like the plague. If you HAVE to drink it, take the regular sugared shit over the sugarfree chemical soup.
Again, just my opinion.