I'm slightly addicted to intensive conditioner, and use it at least once a week on my long, thick, highlighted hair. Right now, it's Umberto Giannini's Spa Rituals Moisture Replenishing Hair Mask that's getting slathered on my locks, and I'm really impressed with the results considering the low price tag of only £4.88.
A lot of cheaper intensive products tend to weigh down the hair and make it limp rather than soft. This doesn't seem to do that, but definitely makes it shinier when it's dry and easier to comb through when it's wet. It's a really nice texture - not as sloppy as some rivals but not as thick and waxy as others - and a little goes a long way (I use one big scoop for my whole head, concentrating on the bottom 2/3). The only thing I'm unsure about is the smell. It's not unpleasant, but it's quite strong and synthetic. Luckily, my super-potent Lush shampoo cuts through, and I'm left with parma violet hair. Yum!