Games should not be remade just to get a "shiny graphics update" as a few users are suggesting in this thread.
Better graphics do not = a better game necessarily.
In fact didn't people hate the ff4 remake for the DS?
Anyway, my point is a game should be remade in order to add features that improve the game as a whole, or to add possible new content.
The Perfect Dark Remake for the XBLA is a good example of this - Yes it had better graphics, but those graphics made sense. In the n64 version the game lagged a lot, and couldn't handle the graphics and all the action screen, dramatically dropping the FPS at times. It also added Online Multiplayer support, Achievements, Awards, and other cool features.
My point is if graphics are to be changed they should have a reason for doing so, and if they add on other features, it should be for a reason as well. Whether they decide to keep the game essentially the same or completely change it, there should be a reason. Something beyond "Because we can" or "Let's cash in on its prior success".
Sometimes a game's graphics can lend to it's overall feel and charm, and upgrading it can make it lose those things.