I never played any. I just saw they are all Economic game which interested me.
1830 - this or any 18xx game, usually takes 3-6 hours and requires quite a bit of power, and definitely other players who also find this interesting.
Automobile - Thick, but not nearly as long
Airlines europe - If you're the kind of guy to ask which one of these three to get, this is the one I would recommend. Economic, but not too rules intensive. The fact that this is a bit of a hybrid of Acquire and TtR, both of which you think pretty fondly of, is an added bonus.