I rediscovered Transport Tycoon last week with the excellent OpenTTD (download the required original data files here). OpenTTD is an open-source rewrite of the original Transport Tycoon engine, but modernized and cross-platform native to OS X/Linux/Windows. Highly recommended.
(Pictured is my Grand Central station in New York, an airport with two monorail lines and four rail lines offering passenger and mail service.)
I’ve been playing this game in bursts every few years since its release in 1995. Me-in-1995 on my 486 would never have believed that I’d still be playing it 12 years later… at 1920x1200… on a Mac.