I recently flew a whole slew of Alaska/Horizon flights. My experience was that the prop plane flights were more generous with their beverage service than the jet flights. I can't figure out why. The prop planes were more likely to give full cans, and came around a second time to ask if they could get us anything else. The jets did not.
Also, I often ask for half gingerale, half cranberry juice. I am often given the full cans of both because they don't want to open them both up and mix them for me because it takes too long.
I also note that the hot chocolate option is often overlooked. No one seems to get it except for me!