Something like the Canon camera that you could change the lenses. The one that takes professional pictures. Something cheap but is worthwhile.
The cheapest Canon DSLR that can record video is the Canon Rebel T1i, which is about $600.
Here are the specs:
Good Digital SLR that can take good video is Canon Rebel T1i .Full HD video capture at 1920 x 1080 resolution
or another good one is Nikon D5000,record 720p HD movie clips