I know this topic has come up in the past on this forum, but here it is again. Back from my first trip to the area (yes, FIRST!, after so many years in the NYC area; what a shame). But I am sure we will go back there perhaps even this summer. So, here are a couple of my thoughts with the hope of provoking a discussion that I could learn from (some of my points are probably overgeneralisations; happy to be corrected).
Cape May - slightly more upmarket, quieter in the night, beach (the one off Beach Ave) is a little more pebbly, walk to the water from the parking lot is shorter, parking is a little more difficult to find, beaches have entrance fees, waves are a little higher.
Wildwood Crest - more like a huge complex of big and small apartment buildings housing the value-for-money tourist, beaches are free, the water is a little farther away (also means more sand to play frisbee or soccer), you can walk into the water a lot longer from the point the water starts because for quite a few meters the water is only knee deep), waves are high but a little less forceful, accommodation is cheaper, the boardwalk is fun at least for the first one or two nights.