I have 3 PCs in my bedroom, two of them use 32 inch LCD TVs (which I can switch to TV mode anytime).
Pro : *much* larger screen size.
Con : lower maximum display resolution settings possible.
The Pro far outweighs the Con, as far as I'm concerned.
Because unless you're some hardcore graphics user, eg. professional graphics artist, hardcore gamer, IT geek, etc; otherwise, you don't even need to use the higher display resolutions (in which everything on screen looks much smaller, as you're packing more pixels onto the same area on your screen).
At standard resolutions (ie. what most people use), there is absolutely no difference in the quality of a PC monitor, and an LCD TV screen.
The Pro on the other hand, is awesomely important. A larger screen size makes for more a much more comfortable viewing experience (whether gaming or viewing movies of *any* kind), and you don't have to strain your eyes to read coz everything is much larger.
I'm using 32 inch LCD TVs coz that was the largest available back when I bought them several years ago. Today, you can (and should) buy even larger LCD TVs for your PCs.