HDPE Nalgenes (branded "Ultralite") are my standard water bottle. Unlike the clear plastic sort, they're not see-through, nor very heat/impact resistant, but they weigh next to nothing. Just don't use 'em as a hot water bottle.

Honestly the water bottles are probably fine as they likely don’t leach much BPA unless something happens to break the polymer apart- like contact with a strong chemical solvent. Although BPA is an endocrine disruptor, it is likely that normal use of a polycarbonate water bottle is fine. They stopped selling them because people got afraid and stopped buying them. I still see no reason to use one given the uncertainty.

You can get really good HDPE, stainless steel, and glass water bottles with a silicon impact cover.