Haven't time to read all this thread, but have picked out bits, sorry if I repeat someone.
We have a king charles cavalier spaniel. She is my second one of the breed, and I would recommend them wholeheartedly as a family dog. They are small, don't tend to be yappy, and have a reputation for good equable tempers (ours is never unpleasant with ds who is 4, even tho he does horrid things to her sometimes).
They don't NEED much exercise, but can walk and run for miles if you want to take long country walks. They are capable of unconditional love, and fit into any lifestyle (my first cavvy used to come to work with me, travelling the length and breadth of the country)
The downsides are
- the hair, gets everywhere, and needs a quick groom everyday, unless you have the dog clipped as I do, she's much happier with it.
- Not long lived, prone to heart problems so choose one from a breeder who has a record of older dogs (Flora's grandmother lived to 15, a good age for a cavvy)
- You can never go anywhere with a cavvy without having to stop every few minutes while people coo over the dog.
Give it consideration. My stepson (who's autistic) was frightened of dogs, but my cavvy got him over it, they're a really good introduction to the dog world)
Oh, one last word. Whatever dog you get, try not to get a REALLY young puppy. Most good breeders would happily keep a puppy for you to 16 weeks, which makes house-training and socialising much easier. Before that it really is like having a new baby in the house, but without the convenience of nappies.