I owned a 2000 frontier in college and it was solid. I drove it to Moab on 35s and IFS, wheeled for a week, and drove back home.
When I picked it up in 04-05 some time, I paid 7k and it had 120k miles. A comparable Tacoma cost nearly twice that at the time.
As for the newer frontiers, they are pretty solid too, but with power and features comparable to a toy. I wheeled with a guy last weekend with an 05 and he beats it up the trails on 35s and IFS.
If I didn't need a full size land yacht crew cab truck for work, I'd own another without reservation.