LCD stats are, umm, not standardized. There are something like 4 or 6 (depending how you group) different LCD technologies, each with their pluses and minuses.
Some viewing angles stats are at 10% brightness of straight on, others are at 5%. (On the "plus side", the angles are so bad on yours, I bet it's at 10%.) Not included in the viewing angle stat, the different techs act differently when viewed from the side: reversed colors (like film negatives), ghosting, fading, or darkening.
Response time is a weird thing for LCDs; the closer the colors/brightnesses are, the slower the change. Black to white and/or white to black are the fastest (which one depending on the LCD tech), which is why they are usually the numbers you see. Sometimes you see GTG (Grey To Grey) response times, which is usually 2x to 4x slower, again depending on tech (and generation of tech). OTOH small changes can be 4x to 10x even slower, again depending on tech and generation.
Generally VGA cable (aka analog) LCD monitors are fuzzier than DVI cable (aka digital) LCDs. This isn't as important for mame as it is with surfing, text editing, and graphic design, though.
I like trying on my shoes before buying. Same with monitors, TVs, stereos, and cars. So as XyloSesame said, see if the monitor is good for your eyes. Big things you really should check out on your monitor are the vertical viewing angles and reversing of colors (if I'm right on the tech). See if people of different heights can see the image on the screen; it would be bad if you could see the screen, but six old kids and 6 foot 6 giants couldn't (assuming you're between those two heights).