Main Street itself is a good candidate. Possibly the "mountains" - Big Thunder, Splash, Space - these are fairly similar-looking at each park but the details are different. Much of the rest of the parks is different enough that you can't do a straight side-by-side comparison.
DLR will also probably will be heavily under construction at that time; I think a huge chunk of Main Street is behind scrims right now. The Matterhorn will be covered in scaffolding. DCA will almost certainly still be a mess, until the big projects wrap up this summer. (I had a big CA trip planned for August so I've been paying close attention, but finally decided that it'd be just too pricey at this point, so back to WDW we go!)
I would probably agree with KCmike - if you'll only be there 2-3 days, you'll probably be busy enough to not have too much time to go wild with photography. The California parks are very densely-packed and notably smaller. Make sure to catch the fireworks! They're much better than Wishes.