I use a Moultrie, IIRC a D-40. Good combination of cheap, good pictures, and sensitive motion sensor. Downside is it takes a couple of seconds to wake up and shoot a pix after it senses motion. Wish I could hack it to never shut down because I'm running it off AC, but if you use it off DC you need it to go to sleep for battery life.
There are better one out there, more expensive. Avoid any that do not date & time stamp the pictures - the cheap ones don't ;(
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