My favorite Tchaikovsky work is his "Serenade for Strings" and then the first three movements of the 6th Symphony ... the march is hilarious and i liked the orchestration in the first two movements. The last movement, well shows Tchaikovsky's weaknesses.
I don't listen to much Tchaikovsky though - I find a good deal of his music both technically and artistically can be a one trick pony with its over the top emotionalism at the cost of compositional technique.