The CE-2 is the best of the three. Very warm and classic sounding.
The CE-3 is similar in sound, (although not exactly the same) and has stereo outs. A little noisy though (or maybe that was just the one I had).
The DC-3 is totally different as it's digital and Boss referred to it not as a "chorus" pedal, but a "dimensioning" pedal. It's more subtle and not exactly the same as a chorus effect, but you can get chorus sounds from it.