Grodd did withstand one of Barry's super sonic punches (Barry broke his hand punching him and Grodd didn't even react). He also tanked getting hit by a subway train and tanked getting hit off a skyscraper.
He also stops an SVU and rips off its ceiling, which is the best strength feat of his I know of.
Overall, I'd say Grodd has the best durability. Juggs is leaps and bounds stronger than he is though. Juggs takes this. Grodd would win if he could use his telepathic abilities, but that wont work as long as Juggs has his helmet on.