[Tricky]

I spend some time playing X3: Reunion this weekend, and I was kind of surprised how much I like the Elite theme it has. Unfortunately though it fails to deliver on a couple of gameplay elements that are IMO crucial, so I'm looking for something else.

I don't know if there is an specific name for this subgenre of simulations, but I was wondering if anyone can recommend me some more games like that. Travelling around, trading a bit here and there, building some cool things and maybe following up on the occasional quest. It shouldn't necessarily have to be an RPG also. Another game like X3: Reunion (with preferably more Newtonian physics) would be cool, but I realize the whole concept of trading and travelling around doesn't necessarily have to be in space. It might as well be for example you on your little catamaran in Waterworld, floating around and trying to make a living by trading stuff in between atoll colonies. Ha.. I think I'd prefer that even. No seriously though, between that and spacey science fiction anything could be interesting. I don't want to limit my question to all these Elite-likes.

I *think* I have seen a few RTS games that had some trade elements in them (something that Sid Meyer might have created), but that's not really what I'm looking for. I don't find RTS games very immersive.

Soo.. break me in fellas, where can I get the good stuff?