Although I don't have any children of the human variety, I have many "children" of the animal variety, or fur babies if you will. I know not everyone has pets or bonds strongly with animals, but my animals are more family members than pets and there isn't anything I wouldn't do for them.
My oldest and most loyal companion would have to be my kitty cat "Haji Baba Prince of Cats". Haji came to me when I was nine years old as an 8 week old furry bundle of stripped spitfire. Spunky, playful and loving, I picked him easily out of a littler of equally stripey kittens living in a playpen in the back of a dress shop. Our bond was instantaneous and he used to follow me everywhere, sleeping curled against my head or on my chest at night. Haji has more personality in one paw than most people have in their entire body. At the young and vibrant age of fourteen, Haji is moody, arrogant, spoiled and vindictive. He's also loving, loyal to a fault, and absolutely dedicated to me. When he wants a snack, he walks to his food of choice and scratches on it until your ears start to bleed. He meows, pesters, picks and whines until he gets what he wants, even when multiple alternative food options available. Deny him long enough, ignore him, or the most unacceptable, go on vacation, and you will find your belongings deliberately peed on while you are watching. He can hold a grudge longer than I can, only drinks water when it's running, likes fillet mignon and cheese, dislikes fish and still sleeps on my chest or by my feet at night.
When I first went to college, I was forced to leave him at home, separating us for longer than a couple weeks for the first time. Not only did he pine, but he mourned so deeply that he became depressed, listless and eventually acquired both food allergies and serious asthma. My chubby boy went from a hefty 15 pounds to 7 pounds and I was scared I might be losing him. After 5 different vets and hundreds and hundreds of dollars he was eventually diagnosed, put on medication and a food restricted diet. He now eats only grain-free organic food, gets a monthly injection of a corticosteroid and a twice daily bronchodilator to control his asthma. The steroid which enables him to breath makes him vulnerable to diabetes and urinary tract infections, so we carefully monitor his health. His last vet visit, another three hundred dollars I don't have to spend, showed that in spite of all his problems he's in excellent health and I expect to have him with me until he's 30.

My next fur baby is my sweet little girl Button, or Buttonwillow McKitten. Button came to me much later than Haji, when I learned that there was a colony of feral cats living on my college campus. While mostly happy and fed by the requisite crazy cat lady, the kittens of these ferals were often eaten by coyotes, run over by drunk or unobservant college students or victims of extreme flea anemia. I couldn't possibly bear to see another squished little body on the pavement so a little under 4 years ago I set out to catch as many of the kittens as I could. At this point, the two surviving kittens were already about 3-4 months old, too old by most standards for socialization. This of course couldn't possibly deter me, so everyday for a week I climbed down the side of the hill that they lived on and sat with my cat carrier and a can of food, trying to lure them inside.
One kitten, the boy, was larger, more trusting and more playful, and would come close to the carrier without too much encouragement. The other kitten, a girl, was smaller, skinnier and much more nervous, following her brother but with great caution. I was convinced that I would be catching the boy first as he would almost enter the carrier to eat the food. Day after day I tried to lure them in, until eventually the little boy walked halfway inside. I really, Really wanted to trap him, but he wouldn't move far enough inside for me to close the gate. After half a minute he backed out of the carrier, and a friend of mine who had come with me took off her shoelace to try and lure him back in. To our great surprise, it was the scrawny little girl who pawed after the string, and after a few breathless minutes she walked into the carrier. It was too good an opportunity to pass up, so I tripped the door closed and she was caught. Her brother on the other hand, being bigger and stronger, was never caught despite repeated attempts and still lives on the campus today. I was able to catch two other older kittens there who had been abandoned, and they found homes with my friends.
Socializing Button was a lesson in patience and trust. I tried every socialization trick I could find but she refused to respond to any of them. Eventually, the turning point came when she stepped in her water bowl, tipped it into her litter pan and got herself covered nose to tail in thick clay litter. Overnight the litter dried to paste in her fur, and by the morning she was not a happy camper. It took me 2 hours to pick and wash the clay from her fur by hand, but by the end of it she was finally mine. After medical treatment for her flea anemia, lots of food, her alteration and her shots, she is by far the most loving kitty ever. She is still wary of other people and extremely shy around strangers (if you're lucky you'll see her fluffy tail slip under the bed), but she adores me and sleeps on her back in my arms and licks my nose and chin at night. She likes her belly rubbed the most, has big golden owl eyes, white ear whiskers and has the softest, silkiest black fur I've ever felt on a cat. She doesn't have a mean bone in her body, lives only in my room and has a dainty sweet little meow. She thinks she's a baby and is certainly my sweet baby girl who nearly gave me a heart attack when we went on vacation last year and she got stuck under the house. My honey and I drove back from Oregon through the night to get home, and he had to go under to rescue her since my boobs prevented me from fitting under the pipes.

Our animal family also contains my mother's rescue Sheltie named "Pippin", a walking sausage on legs, Zena, my grandma's fluffy boy kitty, and Devlin, the mischievous siamese/tabby that I found at a rescue for my sister. Devlin was also difficult in his own way, as he fell off my sister's bunk bed and broke both his hips at a year old. One surgery and over a thousand dollars later, he is a happy healthy 4 year old that spends most of his time sleeping or tormenting Haji and Zena.
In addition to my furry loves, I have a 110 gallon aquarium that I obsess over. It's a freshwater planted aquarium home to my angelfish and rainbows and I don't even want to think about the hours and the hundreds thousands I've sunk into it lol.
What about you guys? Have any high maintenance pets, possibly more work than your human children? Anyone else love their fur babies like crazy whoa?