Are you car-camping or trying to backpack?
We have a Deuter kid-carrying backpack that I highly recommend. It is comfortable for both my wife and I. It's bombproof, has survived two toddlers, and traveled all over the country surviving the baggage handler abuse with hardly a scratch.
For our 2 year old and 5 year old, it's been all about getting them invested in helping with camp chores and getting them little special camping gear items like their own headlamp and their own sleeping bag to get them excited.
Aside from having their own gear items, i can't think of much kid-specific camping gear that we have that makes having the kids along easier. REI has a ton of kids rain jackets, kids sleeping bags, sunhats, tiny kid-sized backpacks, etc to keep them comfortable.
smores are obviously the kids favorite part of a trip.
On one kids camping trip, one of the other parents brought these big ballons that had little LED lights inside them, so we had all these glowing orbs floating around the campsite at dusk. Not camping gear, but that made the trip for the kids, they still talk about that trip and how they loved the 'fairy balloons'.