laurie,

I'm starting to believe those vehicles are constructed with crack...

 

The Titan can get decent hy mpg.I kinda miss my 2wd 2.94 rear end Titan.I sold it several months back and bought the Prius.I don't regret the "trade", but a pickup can be pretty useful.However, I sure don't miss $80 fill ups; the Prius takes maybe $25 every 2 weeks, it gets over 3x the city mpg of the Titan(44 mpg vs 13.5 mpg).
I tracked my MPG pretty carefully; during ~3000 hy trip(evacuation from NO to Flagstaff AZ), I got 20.9 mpg with the bed fairly full(payload was probably 1200 lbs-me, 2 greyhounds in the back seat,bed full of "stuff"). City mpg was a different story; I could get~14-15 mpg in pure heavy city driving, but I had to really,really work at it."Normal" city driving will get you 10-12 mpg(no kidding!).
A 4x4 Titan will cost you 1 mpg-city and Highway, and the lower rear end(3.36) that comes with the Big Tow amd Offroad PK costs you another 1 mpg.If you go 4x4 try to avoid the 3.36.The 2.94 turns about 1500 RPMSs at 60 mph-the 3.36 turns 1750 rpms.
The Titan has had,and is having rear differential problems.Nissan has done a few things to attempt to correct the problem, but I'm not convinced that they have cured it in the 2006's.
Chevys with the right rear end can get hy mpg very close to the Titans-same story on the Ford, but the Titan has a much peppier motor, so it is a lot more fun.The latest 5.3 has been bumped up in power, so it might be a bit quicker(and Chevy is really discounting their CC pickups.)All the V-8 Dodges get miserable mpg(even with cyl shutdown the Hemi is a real guzzler-much worse than the other manu. V-8's).
The resale on a V-8 pickup could drop-a lot-in the future if we get $5 gasoline, but it will still be better than the resale on a V-8 SUV.A pickup can always be used/sold as a "work truck", so it will retain more value than a big SUV-it is a lot more useful for making a $.
If you could wait a couple of years, you could get a "full hybrid" GM pickup.They might be able to get an honest 17-18 mpg city instead of the 10-12mpg V-8 pickups usually get.
Luck,Charlie
PS-I had a Tundra-great truck-about 1 mpg better than the Titan in the city, but it would get just 19 mpg hy when driven very gently(60 mph).
PPS-I'm pretty sure all the 2006 and later Titans are FFV(run on 85% ethanol) and many of the 1500 Chevys are FFV.There aren't many FFV stations yet, but they will be increasing fairly rapidly despite the slight drop in oil prices.They are the same price(more or less) as non FFV trucks, so you might as well go FFV.