The following are the codes for Virtua Striker 2 versions and Virtua Striker 3

Original version: 

To use use FC-Sega, go to Spain, Germany, England, Croatia and

press start on everyone of them. But you have no special match if you are using FC-Sega.               

To use MVP Yuki-chan, go to Japan press start, diagonally right-down press start, down 

press start, left press start, right press start, right start, diagonally left-down start, and finally

down to Russia to press start three times. If done correctly a challenger sound will be heard,

then press three buttons to select Yuki-chan.

To play against MVP Yuki-chan in special match, at the congratulations screen and enter the

above code:- Press start, right-down start, down start, left start, right start, right start, left-down

start, down start three times. If done correctly a sound will be heard.

To play using Virtua Striker 1 background music, press and hold the short pass before pressing

start.

98 version: 

To see a face in the ending, press 1p and 2p start when you see the SEGA title

To see rainbow in replay, before goal replay move joystick up-left and press start.

To change FC Sega formation during game play, press the start button when you see the "select

formation" words at the right hand corner.

To use FC-Sega, Press start once at the country starting with Spain, England, Germany and Croatia 

and press start once at each of them and a small box will appear at  the top then select it. 

To use MVP Yuki-chan, Go to country starting with Y, U, K, I and press start twice. A small box

will appear at the top left corner then select it by pressing the three buttons.

To open ranking mode, after putting your token, hold the joystick down and then press START.

To play using Virtua Striker 1 background music, press short pass and start button after putting in the token.

99 version:

To use MVP Yuki-chan, Go to country starting with Y, U, K, I and press start twice. A small box

will appear at the top left corner then select it by pressing the three buttons.

To see rainbow in replay, before goal replay, move joystick in up and down direction and press start.

To open ranking mode, after putting your token, hold the joystick down and then press START.

To play using Virtua Striker 1 background music, press short pass and start button after putting in the token.

2000 version: 

To open ranking mode, after putting your token, hold the joystick down and then press START.

To play using Virtua Striker 1 background music, press short pass and start button after putting in the token.

To use MVP Yuki-chan, go to countries starting with Y, U, K, I and press start once.

i.e. Yugoslavia, U.S.A, Korea and Italy. A small box will appear at the top left hand corner and select it by pressing the three buttons.

To use MVP Royal Genki, after doing the MVP Yuki-chan code go to the box that appear to

highlight the box then press start and the three buttons.

To use FC-Sega, go to countries starting with F, C, S, E, G, A and press start once. i.e. France, Croatia, Spain, England, Germany and Argentina. A box will appear in the top left hand corner. 

(Contributed by Freddy Fallon)

Virtua Striker 3:

To open ranking mode, after putting your token, hold the joystick down and then press START.

To use F.C Sonic, go to the following countries in the order and press start once. Choose only one team per letter.

S - Sweden, Spain

O - Portugal, Morocco

N - Denmark, Tunisia

I - Tunisia, Spain

C - France, Morocco

i.e Sweden, Morocco, Denmark, Spain, France. (The 1st, 2nd, 3rd, 4th, 5th letters of the above teams form the words SONIC.) A box will appear above Italy. Note: This code will only work if F.C Sonic has been challenged during Special Match

To challenge F.C Sonic during Special Match, at the congratulations screen press Short Pass, Short Pass, Short Pass, Shoot and Short Pass.

If there are any codes that I did not list or is incorrect, please email me.