Even though it was released 7 years ago, SimCity 4 still stands to the test of time.  Direct2Drive is offering the digital download version of SimCity 4 Deluxe (which contains the base game and the Rush Hour expansion) for only $5.  If you have yet to play it, I have to say this is a pretty sweet deal for such a fantastic game – and the modding community is still active thanks to Simtropolis!