First off, take a look at the Monitor Comparisons section of this site to see what went into my decision-making.
The monitor that I went with is a 19" PC monitor from Global Computer Supplies. It's kind of a lower-end monitor as far as picture quality goes - once you get past 1024x768, screen text starts to blur - but since I don't need anything higher than that resolution, it works perfectly for being in an arcade cabinet. All of the games look great on it.
I knew that I'd need a way to hide the "PC-beige" color of the monitor's bezel to make it look so much like a computer monitor. I've seen people remove and spray paint their bezel, but I didn't go this route because I get the odd feeling that doing so just MIGHT void my warranty on it if I ever need to return it. So, I used this heavy-duty black packing tape and just lined the bezel around the screen with it. Once it's in the cabinet, you can't even tell that the tape is there...all you see is the screen.
To mount the monitor in the cabinet I once again bought four super heavy duty triangle-shaped shelf brackets from Home Depot. They're rated at a weight that's way above what I need them to be, but let's face it: that monitor is pretty heavy, and you know that it's going to be subjected to a decent amount of shaking and rocking as you're playing. I wanted to be absolutely sure that it wasn't going anywhere. To mount the brackets to the sides of the cabinet I used 5/8" carriage bolts, spray-painted black.
For the front bezel, I bought a huge piece of black poster board from a local art store. I mounted 1"x3" pieces of wood around the frame of where the monitor would sit (seen here), and then laid the cabinet on its back. I then cut a piece out of the poster board the exact size that would fit in the front of the cabinet and laid that on top of the wood, and then I also cut out a piece of plexiglass the same size and laid it on top of the poster board. With all of the pieces down and lined up, I slowly drilled 3/4" holes through the plexiglass, poster board, and wood all the way around. This was done so that I could use 3/4" carriage bolts to hold everything together.
I took the plexiglass off stood the cabinet upright. I then put the monitor shelf in, put the monitor itself in, and then mounted the poster board to the wood using the carriage bolts. Once everything was lined up and secured, I traced the outline of the monitor on the back side of the poster board (from the inside of the cabinet), and then I took the poster board back off the cabinet. I then measured how far in the actual screen was from the edges of the monitor, traced that on the back of the poster board, and then cut it out using an exacto knife. Once the screen hole was cut out of the poster board, I laid it front-side-down and spray painted the inside of the hole black. I did this because the edging where I cut the monitor hole out was white, so I needed to turn that black.
Once that was done, I printed up another set of of the same arcade characters that I used on the first cabinet and placed them around the bezel.