Don't let the trailors/reviews for Ultraviolet deceive you. Oh, it's bad, all right, but not in that usual cheesy-sci-fi-movie way of predictably lame plot, hollow lines, and action-focus. Those can still be enjoyed on some level. This movie is more like a collection of those cheesy scenes with badly, slowly filmed action sequences and a jumble of great and subpar CG--that is, a collection of those scenes that the editor chopped up, threw in the air, and then assembled willy-nilly. If the plot originally made sense on paper, it's lost now. It's not just bad--it literally makes so little sense that in a number of scenes, we weren't even sure what was going on.
If you want to watch a gorgeous girl run around in pretty effects and sweet action sequences, there are a lot better choices--cheesy or not--and several even feature Milla Jovovich.