Of the guys I know (and this is within EWNCW), TBOZ is the only one I can think of. He's been tag team champion (4 times), WHC once and he's the current Evolution Champion.
Ronaldo Romulus is a tag team championship away, as is Tommy Thunder, Gillz is a mid card championship away.
What would make a GS champ? I get confused with these things!
I thought it was only "Grand Slam" if you won them all. "Triple Crown" I know is the main Championship, Tag-Team Championship and whatever your fed considers it's IC Championship I believe.
Definition on Wikipedia:
The Grand Slam Championship is an accomplishment in professional wrestling. It is a distinction made to a professional wrestler who has won four specific championships or all available championships within a promotion
In that case, I can't think of anyone who's a GS champ in EWNCW, or even close to being one for that matter (very sorry if I'm wrong there, but my memory can be bad with certain things like that!).
I guess that TBOZ is the closest, being that he only needs to win an Ignition Championship, but given that that's a title for newer guys starting off in the fed (newcomers if you will), then I think it's unlikely that he'll ever win it. Never know though, certain circumstances can arise I guess.