this way,you can get 3 starter in crystal/gold/silver without action replay.

All u need to do is do a clone glitch.

-First,start a new game,save games before u get asked about which pkmn u should take. Then,pick any pkmn. And Go through the game until u got 5 poke balls after the first battle with ur rival.

-After u get the pokeball. Catch 2 pkmns,any pkmn will do. Then deposit one pkmn and ur starter,and do the clone glitch. And your game will restart (or just restart it yourself with the clone glitch)

-After restart,the game will load before you choose starter. Choose any starter that u hadn't choose at the first step. And the rest will be easy.

-Get into any town where u can deposit pkmn,withdraw one pkmn u caught at the wild at the first step,then deposit the starter from ur party to the pc. and do the clone glitch. Now,there are two starter in ur pc.

-Last step. Restart game,load,then u should get into the time when u choose starter. Pick the last one that u hadnt choose before. Go to the next town. When u check your pc,another two starter will wait for ya!

Note:

-the clone glitch may broke your save game. (there's a probability that it will broke. but so far,i haven't experienced any)

-any item should be given to the deposited starter to get extra item at the new game. (such as pokeball)

-your pokedex will only get the data of the last starter. The other two will blank. But,when u got those two evolve,then the data will got there,only for their evolved form.