Excellent. It just feels different compared to the myriad of cliched childrens' movies. Rango does a fair amount of its own borrowing (though it took me some time to see it), but it from a different tradition. Rango is grittier than your typical kids' movie. Not of the characters could be describe as cute, but even writers and artists found ways to bring warmth into those hideous faces. Much of the plot and humor is grittier than you would expect for a kids' movie as well.
Beyond that though there is character to the movie. The characters themselves have their own quirky personalities, but even the jokes and scene openings have their own unique twang.
I liked it, and judging by the box office numbers, it was just an experience unique to me.