I am going to have to go with Wolverine and X-23 in a land slide. They are both too tough. I think Wolverine, alone, could take this. Not without a good fight, as Chaos Marines are deft at their fighting prowess, both with and without weapons. But, in the end, it is the healing factor that gives "Team Claw" the edge. Best chance for Chaos Marine to win would be a micro-grenade at close range, he might die, but he would definitely KO the team...momentarily anyways.
I think a better fight, IMO, would be a Space Marine vs. Master Cheif...but it has probably been done.
@Strider92: Could you be more exact on what standard gear the Marine is using? If we are going by the image for gear and using current Plague Marine's then the Marine should win. The death aura, plague knives, blight grenades and plasma pistol is a very hard combo for the healers to get past. Their healing factors will be working overdrive just by being near the Marine due to Nurgle's rot.
@ChaosMarvel: Yep current Plague Marines and yes that is the standard gear (i'll put it in the OP) the only thing difference is the Marine is armed with a bolt pistol. A plasma pistol would be overkill.