Ticket to Ride: Classic Edition

You need to get at least one stock in each company by placing trains on each path corresponding to the symbols nearby and win the game. There are 9 companies to get.

The stocks (and their color/shape) are:
B.R. & P. (black rectangle)
J.C.L (white circle with blue outline)
WM (black rectangle with WM in yellow)
New York Central System (red oval)
Lehigh Valley Railroad (purple rectangle/flag shape)
Reading Lines (black diamond with orange outline)
Lackawanna Erie (green rectangle with white outline)
B&O (white circle with a blue building in the center)
Pennsylvania Railroad (hexagon shape with white outline)

How I got the achievement is getting B&O and J.C.L first since they have the least amount of available stock. Afterwards, focus on winning the game while grabbing the other stocks along the way.

In the Pennsylvania variant, after most claimed routes, you take a piece of stock for yourself based on the symbols next to the route. In a two player game, you also send one to the "dummy player". You can send other companies to the dummy player. For this achievement, you need to get at least one stock from each company before winning the game. The only advice I have is start out using your first few turns to claim routes for the two companies with the smallest shares (BR&P, the black rectangle, and JCL, the white circle with a blue border) just to make sure the CPU doesn't claim them all before you get a chance to get one. After getting those two, you can pretty much play the game normally just making sure to take stocks you don't have yet when possible. If you need to check which stocks you already have, owned stock shows up at the bottom of the screen after pressing Y.