I generally take on each trip:
2 L Platypus bag (for collecting dirty water - doubles as my pillow)
1/2 L Sawyer bag (for the rare powdered drink mix)
1 L Powerade/Gatorade bottle (what I normally drink from)

I've not had a problem with the Platypus or Sawyer bags not standing up on flat ground without a cap.

As you mentioned, I have lost 1 empty Gatorade bottle while bushwhacking down a brushy, steep hillside.