"*Most often* my money's on Logan, for the following reasons.
Most of them will be centred on him, as he's the only one to fight all of them.

Deathstrike sucks. Badly.
She was humiliated by Wolverine so she turned herself into a cyborg to kill Wolverine.
She didn't do so well.
So then she tried again with an mini-army of cyborgs and managed to crucify him.
Later on X-23 beat her by herself.

X-23 seems to do well vs Wolverine, but he generally doesn't want to hurt her.
If Wolverine didn't consider her to be some kind of weird sister-daughter hybrid of a relation to him, then he'd likely nail her.
She also pwns Deathstrike in their only fight ever.

I would say, on paper, that Wolverine should beat Deadpool more often than not (when they're equipped as they normally are.)
They've both won encounters with eachother, BUT giving Deadpool adamantium will make it one epicly long and boring fight.
Wolverine can decapitate Deathstrike (I think), and certainly X-23, which is the best way to beat ALL of these guys.
Deadpool with adamantium couldn't have his head removed.

On paper, Deadpool's best advantage over Wolverine (excluding his mouth) would probably be his weaponry and the skills involved. Wolverine's over Pool would be his skeleton.
Giving Pool the adamantium might be too much to handle for ANY of them.

/nerdtalk over "

"I was thinking of Deathstrike like she was in X2."