I like most Tamiya and Dragon, and the newer Trumpeter. I like some of the Revell AG stuff, and some of the Academy and AFV Club offerings.
For aftermarket or limited stuff, Formations is extra nifty. So are the Eduard barrels (hussah!), WWII Productions treads and Accurate Armour sets.
I consider photoetch and resin zimmerit to be necesssy evils, so I won't comment on them.