I have a '00 (first year) tundra 4x4 (4.7 2UZ-FE) with slightly over 243k miles.
Engine runs great, strong trans, A/C is freezing, and heater is hot.
The closest time it ever came to breaking down is when a coil pack went bad and I had to misfire limp 60 miles back to civilization to find an Orileys. Luckily it didn't hurt my catalytic converters as far as I can tell.
I've replaced the following things since I've had it the last 2 or 3 years (second owner, bought it with 225k). Some of it necessary, some of it preventative:
Radiator (top tank seam started leaking)
Spark plugs/coils (one bad coil, replaced them all)
Timing belt, water pump, fan pulley (preventative)
Rack/pinion, inner/outer tie rods (leaking and bad bushings)
Lower ball joints (mostly preventative)
I consider it all well worth it. I think she'll be good for another 200k miles easy. I did all the work myself except for the timing belt and water pump. Pretty easy truck to work on and I love it.