Hmm, well I am in no means a card expert but from playing I've got a few ideas for the vital cards.
For Guardians I would generally always take Machete (perhaps 45 Automatic if you have good resource gain), Dodge, Vicious Blow and either Beat Cop or Guard Dog (Beat Cop is probably better for Guardians but they are both good allies). Machete is such a good weapon is makes most of the others completely useless and Dodge and Vicious Blow are just damage reduction and increase which are vital for Guardian players.
For Seekers, I would take Deduction, Mind over Matter and Dr Milan Christopher. Milan is arguably the best ally in the entire game, the resource gain from him is insane and he directly fuels Higher Education which is a bananas powerful card you will get from a later pack. Working a Hunch can be useful too for the once in a blue moon when you fail an investigation check. For Daisy in question, all the tome cards are great and worth taking too with her character power.
I'm not familiar with Rogues so well, but I would say Leo De Luca, Backstab and Elusive are all solid cards.
Survivors, like Rogues I am also not 100% used to, but I would say Lucky! and "Look what I found" are vital (in fact I would go so far as to say Lucky! might be the best 0xp card in the entire game). With Wendy Survival Instinct is also a great card. Annoyingly, Survivors have a lot of their best cards locked behind future sets but if you progress with them then Fire Axe, Dark Horse and Peter Sylvestre are worth keeping an eye out for.
Hope that helps.