V6 was better choice for me.
I have the 2003 V6 4WD Limited. I have 19.5k miles over 15 months. I chose the V6 for the reasons already stated above, i.e., more practical for my driving needs, switchable 2wd to 4wd, etc.
I test drove both V8 and V6. I could tell a slight difference in the feeling that the V8 seemed to have a more powerful feel in the acceleration than the V6. But it wasn't enough to convince me to buy the V8. FYI, I also owned a Sequoia V8 4WD for 2 years and that poor gas mileage was one of the major reasons I didn't want to pick another V8, granted the 4-runner is lighter in weight than the Sequoia, I still needed a worth while improvement at the gas pump.
I have definitely not regretted getting the V6. For the winter snow trips in the mountains, that 4WD kicks butt! For the summer trips to the lake, I thought I would never tow anything. But just this year, I purchased a SeaDoo Personal Watercraft (PWC). With the trailer, PWC, and gear, the load is about 1500 lbs. I have no problems pulling my PWC in 2WD on the road. In fact I can't even tell I'm pulling anything. The only time I really feel like I'm towing something is when I'm braking. When loading or unloading the PWC in the water, I'll sometimes put it in 4WD to get more torque on the loading ramp. I don't need to go into 4WD, but it was nice to be able to switch it ON.
Most of the time I'm in 2WD to and from work on side streets and freeway. V6 and 2WD is definitely a benefit to me. Less visits at the gas pump. I use 87 octane and have seen no problems.
As far as reliability of the 4runner, it's second to none. Sure I have had the serpintine belt and tensioner replaced, have had the fuel pump recall service, and took care of that annoying moonroof rattle, but after all those issues were fixed under warranty, I haven't had any problems.
Initially I thought I should get the V8 since I owned the Sequoia V8 (I guess it was a guy thing to get the V8), but I'm over that and I am a satisfied owner of a V6.
-Gene