It's clear who the best SG, SF, and PF are. I'd say 90% of the basketball community would agree that they are Jordan, LeBron, and Duncan, respectively.
C is a mixed bag of what era you adore/watched the most.
PG was easily Magic until Steph came along and created a convo because he's not a "traditional" PG like Magic Isiah Stockton Kidd CP3 etc.
Steph is the best floor spacer and one man system the modern game has ever seen. For that reason, plus all the records and hardware, I'd go with Steph. But it's a convo and I don't think either side is wrong to back their horse.