I have played D&D Basic, Expert, Advanced, 2nd Ed, 3rd Ed and 4th but not 3.5 or Pathfinder. Loads of short times playing non D&D RPGs too but not ever as much as D&D. I liked the old basic and expert as it really had that Gygax feel to it. Very raw and interesting with a strong lean on the fantasy side. By 2e the rules were complicated and had a lot of anomalies to them but I had my best D&D under that system. Did a little 3e - liked the way it was all unlimited and more linear than previous rule sets but didn't particularly like the feats and skills approach. I am enjoying IGs 4e Witchlights campaign but kinda in spite of the 4e rules. I am finding the rules a little style cramping. I don't like the second wind and these set piece abilities. There's still scope for role playing but there's no doubt that the rules have diminished the role playing choices that you can make if you also want to be effective in a fight. Outside of the fight and dice stats tho there's nothing stopping all the usual role playing.