The first gen of Pokemon games.
These 3 games started it all. Red and blue came first, then yellow was made to be like the anime. Most people were into Pokemon back then, which was good.
..::Glitches/Cheats::..
Missingno/'M (Red and Blue only) - The well known hall of fame buggerer upper. OK, this is actually a duplication cheat, so stick whatever item (not like the town map or bycicle, cloneable stuff, RARE CANDIES! ^^) in 6th place on your item list. Flyyyy to Viridian City, and talk to the d00d who teaches you how to catch pokemon. Let him show you then Fly to Cinnabar island. Surf along the land's edge, as shown below.

You might run into a level 136 Golbat *shudder* or a level 200 Snorlax, but run from the buggers. Missingno will pop up, and run from him too. Back on land, dadadada! 129 of the item in 6th place on your list. Yes, it does work multiple times. ..::Cheat officially works::..
Glitch City - This place r0x0rz. XD Ok, go to the safari zone, enter, save, switch off. Switch on, exit, say no, wait for the infamous DING DONG and tada. You be in Glitch City. And for God's sake, have fly on you. ..::Cheat officially works::..
Stand on a Tree - This is lame, but funny for those, including myself, who are amused by stupid little things. Cut down a tree, stand in the spot where it was, save, off, on, tada. ..::Cheat officially works::..
Mew under the Truck - OMG if u sufr past sss ann and yuse strenff on dat tr00k mew will be undor it yay. I have tried this, and have found NO truck at all.
Mew in ze Wild - Ok. If you have battled that d00d with the Slowpoke on Nugget Bridge (near Bill's house), no mew for youuu. If not, fly there and LET HIM COME TO YOU! Battle him, save, fly to Celadon, go thru the underground path, and as you come out the other side (haha), PRESS START VERY QVICKLY. Fly to Lavender town and go west to that route (west is left :P). Badingdingding, you battle Mew. Its level 7-8, so use an ultra ball or something. :) ..::Cheat officially works::..
..::Top 10 Tips to Keep Pika Happy::..
Yellow, obviously. :P
- Give him potions when he doesn't need them. And give him a lot. XD
- Keep him in your party.
- Level him up lots.
- Don't trade him. :PPPP
- Don't deposit him.
- Heal him faaaaast.
- Use him in the Hallofame XP
- Walk with him a lot.
- Don't let him faint too much.
- Let him fight in lotsa battles, EXP All is crap.