Mark Ruffalo’s Hulk has been a huge part of the Marvel universe since the The Avengers, but his version of the character has yet to have a solo project (Edward Norton starred in The Incredible Hulk).
When last we heard of Bruce, he had found a balance between his Hulk self and human self known as Smart Hulk.
He may not gravitate toward avenging, but could be a worthy consultant to She-Hulk as she deals with her new powers.
But coming down the pipeline, She-Hulk will have her own TV show starring Orphan Black’s Tatiana Maslany.