Take: Orange>Red>Light Blue (Orange is the best by far, Red is good too, just a little more expensive. They actually get a similar number of hits (Orange is hit a little more). Light Blue is good because of its spot away from GO, likewise Orange is great because of its position by Jail.
Avoid: Green<Purple<Brown (Green, while it gets average traffic...costs way too much to develop. If you have to block a monopoly do so. Purple is right next to the jail and is almost useless later in the game. Brown does not gather enough money to be useful even at the low cost.)
Up to You: Dark Blue and Yellow. (Dark Blue is a risk, but if you develop it even one land on it can bankrupt a player.)
Take: Railroads
Avoid: Utilities
If I remember its best if you develop 3 houses max on a property (gives the best cost to profit ratio)
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Chrono1219