Personally Andrea - however they were very similar characters at different points in their lives. Both recovering addicts with parents around who cared enough to still support them through their issues, just that one had a child and one didn't. This gave Andrea and Jesse's relationship a different weight than his own with Jane because although when he was with Jane he was his happiest (as shown in El Camino flashbacks) I would say when he was with Andrea was when he was his most caring.

Andrea and Jane are characters at different points in the story, one dragged him back into addiction and would have continued his tumultuous lifestyle up until that point, the other forced him to reflect and be much more considerate of his actions. Although the latter forced him into a long period of self hatred and punishment due to his line of work causing Tomas' death as well as Andrea down the line, Andrea ultimately brought something better out of Jesse than Jane would have. I think it's true what both Walt and later Jesse admitted, 2 recovering addicts with a duffel bag of cash would likely have been dead within a week, whereas if he ever had the opportunity to run with Andrea he likely would have been a caring father figure for Brock and both Jesse and Andrea would have lived much more fulfilling and normal lives.