First things first--center channel speakers do one thing really well--they anchor dialog to the screen for listeners sitting over to the left or right sides of home theaters. So if your family or friends watch movies together, I'd definitely recommend using a center channel speaker.
But for one or two people sitting directly in front of their TV a center isn't necessary, and almost always sounds less good than the left and right speakers. Center speakers tend to sound boxy, so Denzel Washington sounds like he's in a box. Ditch the center and your A/V receiver will redirect the center channel sound over to the left and right speakers. They have the advantage of not being in front of a display, which unfortunately acts like a large reflector behind the center, which messes with the sound. You will of course, need to go in the receiver's speaker setup menu and "turn off" the center channel speaker output to implement the change.
Also, the typical horizontal woofer/tweeter/woofer center design is a flawed concept (three-way center speakers that centrally position the midrange driver under the tweeter are better). In any case, center speakers rarely tonally match the left/right speakers, upsetting the illusion of a seamless soundstage. Yes, the center's responsibilities loom large--on movies the center conveys almost all the dialog, a lot of effects, and some music. That's why all of that will likely sound better over the left/right front speakers. Oh, and it wouldn't be a bad idea to "rechannel" the money you saved by not buying a center speaker into better left/right speakers. That strategy would result in better overall sound.