I've never been to Disneyland, but I did grow up in Orlando, FL where we went to Disney World (Magic Kingdom, Epcot, Hollywood Studios, and now Animal Kingdom) constantly. I've never gone more than a few years without going back. Disney World is a huge tradition in my family. When I have kids, I am definitely planning on taking them as often as possible. I couldn't imagine my childhood without it, so I would say it is WELL worth the money.
You can get stuck standing in line all day if you don't plan your trip correctly. Disney has fast passes at each ride where you can scan your park ticket and you get another piece of paper that tells you to come back to the ride at a certain time of day and you'll be able to use the fast lane to get to the head of the line for the ride. If you get there when the park opens, you can go ahead and grab fast passes for the more popular rides and while everyone else is waiting in line for those, you can ride the less-popular ones with little to no wait. Also, if you don't think your kids will enjoy the parades much, you can ride the rides during parade time and you'll find much, much shorter lines then, as well. It also depends on what time of year you go as to how long lines will be.
But as someone who grew up taking in the magic of Disney theme parks, I would say it's well worth it to take a kid. And even as an adult, I still have a huge love for the parks. They're definitely expensive, but it's a fabulous experience if you plan it correctly. There are endless websites out there that do nothing but offer tips, advice, and outlines for how to make your trip to Disney a great one, so I'd definitely suggest checking those out to help make the whole thing less stressful.