I also bought a Fitbit One and i love watching my steps throughout the day. It also pushes me to get of the couch and workout a bit.
I have a Jawbone UP. And it works really well. Helps track work out and my sleep habits. I work for AT&T and we have a few of the fitbits available. Some work well, some are more novelties.
I'd recommend waiting till after Google IO (June something or atother). Lots of new stuff, including Android wear devices to be announced. Many of these will have fitness tracking capabilities. I'll post more later.