i made a bezel out of posterboard, i was very unhappy with it. then i spray painted it black, which made it darker(the black posterboard is really pretty gray), but it got wavy because it was too thin and was moist from the paint. then i completely got rid of that, masked off the monitor area and spray painted the back side of my monitor plexiglass. this made the monitor plexi and bezel the same piece. i am very happy with the way this turned out. i used flat black spray paint (the stuff you get for .98 cents at walmart). from the front side, it looks very glossy and nice. the only down side to this is if you ever replace your monitor, or want to rotate it or something, you will need a new piece of plexi.
i don't have any real good pics, but here is one that kinda shows how it looks. there are a lot of smudges and fingerprints on it in that pic, but you get the idea.

the 4 round things are magnets that i used to hold it in place, but since i modified the supports a little, i dont need them anymore, it just sits in there nice and snug.