With trucks over the last 20 years I went from a Toyota to a Ford to a Nissan to a Chevy and am now in a Ram so, obviously I'm not exactly brand loyal.
Of the truck you mention, the Tundra would be at the top of my list. I owned a 99 F150 with the 5.4 - the engine is an underperformer for the mpg and pretty much started to self destruct at 100K (something called "piston slap" - didn't sound good). The Silverado with a 6.0 is a nice truck from what I've heard (my Chevy was a diesel so I have no direct experience).
Mainly, as others have said, drive them, do some research and pick what works best. Before trucks I drove many Toyotas and was always impressed with the reliability and durability. If they'd ever start making a 3/4 or 1 ton full size truck they'd likely sell one to me.
