I've had good luck with the Canon Powershots.
I had one that ran off of 4 AA batteries, and it was fine until I dropped it. oops.
The next one ran off of two AA's, and it tolerated being in a sweaty bike jersey pocket quite well. Easy to just grab out of the pocket and use it with one hand. Simple user interface and good results.
I did upgrade a couple of years ago, though. The new camera is a Canon Powershot Elph 350HS. I think it was about $150. It has a 12x zoom, a few more features, better low light sensitivity, ability to take HD video, etc. It's much less bulky too, which is appreciated for bike use. Overall, I'm quite happy with it.
Steve in Peoria