I can't really say that my mate Apollo is too much hard work, honestly! But then again, I've invested a lot into a nice cage, misting system, timers, and other things that make the upkeep almost automatic.
I do have to say that I check everything up every single time I get back home, but that takes about 20 seconds each time: Look at the feeding cup to see if he's eating, look for poop to clean (and check for white urates), look for the water level in the misting system reservoir to see if it needs filling up and look at the humidity and temps in the viv to see if everything's okay. If something's out of order, I just correct it.
Every morning I put some mixed feeders dusted with what's on that day (I have a calendar next to the suplements saying which one should be used that day).
Every 2-3 days check the bugs for dead ones and change their food/water so that it doesn't rot. which takes about 10 mins...
I buy crickets in bulk (200-300 at a time) and order 2 cups of different feeders (dubias, wax worms, tiny superworms, mealworms, and some random bugs that might show up at the website I use).
After that, it's just really enjoying him interacting with the environment (and sometimes with you). It really is amazing watching them eat. My chameleon enjoys having his cage door open when I'm home and comes to the top of it so he can bask a bit in the sunlight coming from my window.
Honestly I have to say that they're a lot less work than for example a dog (if you live in an apartment) as you don't need to walk it X times a day... and I enjoy the fact that they aren't always nagging you for food/affection, but then again, my chameleon lets me handle him whenever I want and enjoys roaming around the plants in the living room/balcony.
But if you do decide to get one, follow what the senior members here say, as their knowledge really does wonders.

Especially Jannb if you're going veiled (they are awesome). She really saved my chameleon more than once whenever I asked around here