I have a 2005 Jeep Grand Cherokee. 3.7L V6 4x4. On average it's about 16.8mpg. When I'm beating around town in the snow or with the AC on, maybe 15. If I'm cruising at 55mph on a highway with no stops, I can squeeze out 22mph in the best of conditions. Cruising at 75mph on the highway gets me about 19 on longer trips.
On a side note, I just test drove a Subaru Outback. I wasn't impressed. I thought it would be a nice transition away from the Jeep for better gas mileage, but saving only $400/year in gas didn't make sense since that would be like 1.5 payments on the new car! I guess you could figure in life of a new car and maintenance, which I will certainly start seeing having a 12 year old Jeep with 126K miles. I've taken such good care of it though, I can't give it up. It looks better than many 6 year old Jeeps and I could say the same for the condition of the under body/frame. I guess I'll keep my eyes open for a good used Jeep for when mine dies.
At $2/gal...keep pumping and I'll keep burning it up!