I think the HBO production of Rome got most facts right regarding costumes and settings. But regarding historical accuracy of events...
I also recommend "enemy at the gates" just for that opening scene, and "The Last Samurai" for portraying that era of modernizing in Japan even though both of those movie invented its own character for more entertainment to the plot.

As for the worst ill have join the bandwagon and say 300. Hated how they had to get monsters instead of proper Persian soldiers. But then again its based on graphic novel..