I voted for Barry.
He & Hal first teamed up in GL #13 (1962) - I have a nice copy
Then again in Flash #131 (Sep 1962) - I have a nice copy of this one too.
Hal & Ollie didn't team up (I think) until 1970?
Hal & Ollie's friendship seems bigger as the Adams/O'Neil run has become SO iconic.
Personally, I don't think the stories have aged very well at all, but different strokes for different folks.