My commute M-F is 60 miles round trip. 80% highway, 20% multilane road with numerous stoplights. With the a college student's budget, I needed to figure out some way to save gas and have I ever! I'm sure I'll get grief from some, but with numbers like 33mpg I can deal with it.
In the morning, I will drive 65 on cruise control and off the highway I will try to be in 5th gear if at all possible. On the way home, 60mph on cruise does the trick. My AC is broken, so I run windows and sunroof open and can only afford to fill up with 87. I typically will only drive 300-310 miles per tank as I need a new fuel pump, but getting that mileage uses only about 10 gallons.
Every once in a while I will still have some fun on country roads, but my mileage has consistently been above 30mpg while driving like explained above. I've gotten my GF to drive the same way in her '00 Jetta VR6 and she is putting down mileage numbers upwards of 29 as well. The name of the game as far as getting higher numbers is the way that you drive. Don't idle, no hard launches, blah blah blah. A soft touch on the pedal will save you lots of money at the pump.