I first experienced in person trading in EQ and mostly did not like it. Too many people would get mad at an offer, call you names, and put you on ignore. Maybe I just sucked at trading lol. But sometimes it was enjoyable. It definitely felt more like a community, dealing face to face.
In SWG, I loved in person negotiation - especially player shops. The craftsmen had reputations to uphold, and tended to treat you fairly. Plus they were often skilled players you could chat with and learn from.
Since then it has been mostly auction house trading. That is my personal preference. Item goes in. People buy or not, bid or not. I like the simplicity of the system. What I don't like is people buying all of something and then price gouging.
Which do you prefer?
EQ1, EQ2, SWG, SWTOR, GW, GW2 CoH, CoV, FFXI, WoW, CO, War,TSW and a slew of free trials and beta tests