It seems to me like much bigger than a 17" is pretty unwieldy. My 17" Samsung is kind of a pain to lug around to LAN parties, I would have gotten a 19" but I think that would have just been too big & heavy.
Also, when you go to LAN parties, there is sometimes limited desk space (in my experience). 19"+ monitors have such a huge footprint, I wouldn't be able to use one at my friend's house where we go to play.