OK here's a question for you all, sell me the benefits of a dog puppy or a bitch puppy to be kept from my  bitch's litter.

I am in a dilemma, all gorgeous, but who do I keep?

The one you like the best! Sorry, not a lot of help, but unless you have a specific purpose for it, choose the one that keeps attracting your attention.
:)

Is there a particular reason for keeping one, ie; showing or pet only

Oooh that sounded bad, but you know what I mean :)

No its a good question Kay.

Is the pup being kept as a pet - for show - for breeding.

I'd keep the best or the one that appeals to you the most. One must if not don't keep any.

Sorry to be harsh Karen

Well to be honest, If showing, obviously you have to keep the one which resembles the breed standard best. If as a pet, then as JG says, follow your heart.   In my litter I had to make a choice of 3, whittled it down to 2 and the only reason I did not keep Ollie was simply because I did not want another adult dog in a housefull of bitches. So although I bonded more with Ollie, (he was nearly 5 months old before going to new home)  Ellie stayed. :)  But, Ollie comes to my dog training classes everyweek so still get my cuddles  :D  It is very hard but you really need to be quite tough about it. 

Thanks - yes it is very tough as it's my first litter, probably won't show, puppy is our pet first and foremost, although bred from really sound, healthy show stock.
Yes I will have to break my heart, but as you all seem to say - gut reaction- one final point though is it fair to keep a neutured boy with an entire bitch - eg. if I keep a boy will that be OK if I keep mum entire? As this litter has been so enjoyable may consider another litter in the future. Don't worry not for at least a year...