Ok so I'm far from an expert compared to some on here but can probably help you out;
Firstly queues for characters in disneyland paris are enormous. Partly because you spend more time with them, have a full interaction etc and partly because Europeans love characters (and there are less rides to do). Mandalorian (3 hours+), jasmine (2 hours +), a single random princess is usually 2.5+ hours, vs california where meeting all 4 is usually 15 min or so. Anna and elsa never do Paris because the whole thing would become a farce.
That said, I have had brilliant unscheduled interactions with Jack Sparrow and Mary Poppins when they were roaming unannounced. Also, character dining is expensive but nowhere near the levels of either US park, and with a meal plan is good value IMO. If you stay in a disney hotel onside (again, more reasonable prices than US parks) you'll also get a character each morning.
And if you really want to do it in the park and don't mind queuing, then stitch, winnie, alice & friends, goofy/max, woody/Jessie and the main 5 seem to be the ones that paris love to shove out there.
