Just about all of my pets are rescues. My 3 cats, 1 horse, 1 donkey, my 2 dogs are all rescues. Only ones that aren't rescues are my fish and chameleons.
Well, allow me to put a little rain on all this sunshine by pointing out rescues aren't for everybody.
Usually they come with some sort of problem- either medical or psychological and not everyone is equipped to deal with those problems.
Recent examples here on the forums- the melleri "rescues" that lasted no more than a couple of days before dying. Those were anything but "the best" pets. The owner was well intentioned in their "rescue" by purchasing them, and bless the owner for that intention, but that isn't enough to turn some rescues around.
Here's another- my sister got a rescued dog from a shelter. The dog was OK with adults, but freaked out when kids came around. Scared my first grader to death when we visited because the dog would snarl at him. Sister and hubby thought the dog just needed some love and training. It got plenty of both. All seemed well. Sister had first baby (real baby not animal baby). Dog and baby got along great until one day baby was a toddler. Sister, toddler and dog are all together in living room, all is peaceful. Toddler is lying on floor napping. Suddenly dog gets up and chomps on toddler's head, sinking teeth through skull. Toddler gets plenty of surgery for wound and to look normal again. Dog gets to go live with grandparents (it isn't dog's fault he's that way). This "rescue" was hardly the "best pet ever".
Here's another- I took in a huge 18lb iguana after it nearly removed an elderly woman's finger. She loved him like a baby even after the bite and surgery to save the finger, and even though she nearly lost most of the use of that finger even though it was still attached. Think that lizard made "the best pet?" I didn't- he was gorgeous and I gave him a good life, but I had to be on my toes every time I entered his walk-in enclosure.
Here are a couple dozen others- in the early 90s when the iguana craze was in full swing, people knew I liked lizards and I ended up having a lot of iguanas dumped on me over a few years time. Nearly all came with a lovely case of MBD and psychological problems resulting from ignoramuses neglecting them. You can't take an iguana and toss it in a cage and toss food and water in and expect it to be any better socially adjusted than a dog who you treated the same way. People didn't get that. These animals needed real help- corrections on diet and husbandry and socialization on a regular basis- sometimes including biting on their part and bleeding on my part. Most would not reach full size or look right, thanks to the mbd from their ignorant owners. These were far from "the best pets" as well. In less experienced hands, these may not have recovered or socialized.
If you are lucky you can find a "rescue" that is in good shape and does not come with problems of some sort. But many do- either physical or psychological. Most people are either too ignorant to know how to deal with these problems, or cannot afford to deal with these problems, or do not want to put in the effort to deal with these problems, or do not have a lifestyle that allows them to deal with these problems.
Bless everyone who is "right" for rescues and can truly provide them with a suitable situation. Because many rescues are far from "the best pets". Many well intentioned individuals without the knowledge or experience to provide these animals what they need would be better off trying to succeed with a healthy animal and seeing to it that it gets the best care and a permanent home so their pet never goes into a "rescue" situation in the first place- a way to deal with the same rescue problem from the other end of it by preventing it in the first place.