Heh, it depends.
Sports? Anime all the way.
Action? Usually manga unless the animators did an amazing job. Bad and mediocre action shots lose me very, very quickly. Repetitive gestures get old especially fast, too, when animated.
But then there's quirky little things like an artist who doesn't put enough variety into his character designs, and anime can win out just for ease of recognizing because of the colors.
Most of the time, though, I do prefer manga, and by a lot. It gives me more control -- for certain characters I might slow down and mentally add dripping scorn or whatnot to their lines. Or I can read quickly~ I'm not at the mercy of a voice actor or someone else's idea of how the scene should flow. If I missed something it's easier to reread a page or panel than fiddle around with a track meter.
Then, there's the curse of the flashback and the bane of the recap. A flashback/recap that doesn't add anything new is a page skipped in a manga. But in anime, it's downright obnoxious.
Sub vs dub... I don't mind either more often than not. Dubs are somewhat more likely to have an inexperienced voice in the cast, although that's gotten leagues better in recent years. But on the flipside, I think dubs are a little more freeing in that I can put more attention on the art and expressions. Also, as a native English-speaker, a lot of English words/terms/phrases/titles suffering from consistent mispronunciation from a Japanese voice actor will bother me a lot (looking at you, Trigun).