Weak opening, but it gets better further in.
I bought Tropic Thunder movie along with Black Hawk Down a while ago, as I had heard good things about it.
Yeah, the opening with the faux trailers isn't particularly funny and Jack Black's trailer in particular had me worried that the movie would turn out to be nothing but toilet humour. Turns out my fears were unwarranted. Okay, there's crude humour aplenty, but the movie gradually gets better. The best part of the entire movie is Robert Downey Jr. who remains consistently funny throughout the entire thing.
It might not be the classiest comedy, but it's worth seeing.