I haven't really paid any attention to the Adventures strategy talk, so I suppose this is probably already well known, but I came across a combination of cards that seemed to work very well together. The basic combo was Duplicate + Ferry, and I added a few other things to make it run a bit better. The idea was just to buy Silvers for a while (I actually got an Amulet to gain Silvers, but I think this may have been a mistake), then pick up a couple Duplicates, and put a Ferry on the Province pile. Then to get multi-Province turns, you just need to spike $6 on occasion. It's big money with no Golds!
This plan was helped along a bit by Scouting Party, to sift through the junk in my next hand, and Wine Merchant, to help me get $6 with my crummy deck: I didn't mind paying the $2 on off-turns to discard him, since $2 was sometimes all I had after Scouting! I didn't count the turns, but I seemed to have 5 Provinces quite early, and wasn't slowed down enough that I was worried about an engine coming from behind while I finished them off.