I sold high end audio video for about a decade and have been an avid gamer since the Sega Master System days. Right now I have a wide screen Toshiba 30'' tube with HDMI and component input which I use with my modified original x-box full of SNES games and my Wii. the component cable makes a HUGE difference.
Here are some suggestions, the PS1 had optional S-Video cables which are worth investing in, as you will see an immediate improvement in sharpness. the other consoles use composite cable or coax which might require you getting a switch box to make things easier for going between consoles. Play with the color and contrast setting to get things just right for your room but remember that the setting might need to be altered depending on the source you feed to the TV.
Try and spend about $50 on a serge protector (no more) because these sets never liked peaks in voltage and your console are probably worth a bunch as well.