Especially All Things Must Pass, his triple album release of 1970, produced by Phil Spector. By that time Harrison had compiled quite a backlog of great unrecorded songs due to being relegated to (pretty much) only one song per album when he was with the Beatles. He must've felt like he was just let out of jail.
He made remarks to that effect after the Beatles broke up.
The Beatles broke up at precisely the right time, had they gone on further, their legacy would have been tarnished.