I know at one time she hulk had the ability to break the fourth wall. knowing (or often hinting to) the fact that she was a comic book character. does she still have this ability and what other comic book characters possess this "power"

Loki can too. I think Shulkie can break it now and then too. 

i think breaking the fourth wall is the coolest power in comics.

I too feel that the Fourth Wall is one of the most fun concepts out there.    
If you go to the Fourth Wall concept page you'll get a list of several characters that have either broken the wall before or still do. It also makes mention of an interesting concept known as the Fifth Wall.  

I have always enjoyed She Hulk's hilarity, but Ambush Bug has always done it the best

She-Hulk breaks the fourth wall in Marvel vs Capcom 3 and even says to Deadpool that if the game was made in 1991, she'd be the one doing all of the fourth wall-breaking.

" Nope, she doesn't have that ability anymore. It was addressed in She-Hulk volume 3 I think it was. When she was working in the superhuman law division of that law firm.

" i think breaking the fourth wall is the coolest power in comics. "

I remember shulkie breaking it in "She HULK Cosmic Collision". In 08.