I am a water bottle junkie. I have like 5 or 6 and buy new ones rather frequently. I always take a water bottle to class and to work. I have three favorite types which I use most often.
I have one Camelbak water bottle which I got at the school book store. It has my university logo on it and is one of my favorite water bottles.
I have a Waterbobble in pink. I got mine from Old Navy. I love it. It is my other favorite water bottle. When they are new the first couple times they are used black beads come out of the filter, they go away after the second of third use though.
I have several of the aluminium water bottles in different colors and brands. I like them but I am a bit of a klutz so I tend to spill them all over my face.