Best:
Wally and Linda
Arthur and Mera
Clark and Lois
Pre FP Midnighter and Apollo (Orlando tried his best tho, I'll commend him)
Hourman and Jesse Quick
Ryan and Giganta
Worst:
Bruce and Diana
Clark and Diana
John and Fatality
Barry and Patty
J'onn and Kendra (Snyder.. what..)
Donna and all the manchildren she keeps dating (Kyle, Roy, and Terry)
Joker and Harley
Ships that had chemistry but you know they're a hot mess:
Batwoman and Renee
Hal and Carol
Ships that were good at one point but they just need to let them go:
Dick and Barbara
Dick and Kory
Ships that could've been good had they actually done more with it than just a tease or whatever:
Dick and Kate Spencer or Helena Bertinelli (pre FP or post FP)
Piper and Singh and tbh Piper and Trickster had they had the guts to do it cause it seemed like they were gonna go there before they killed him.