I'll be using Red, Gold, Ruby, Diamond, and White.
Gonna have to hack all the way through White. xD I'll hack in the starter, and then another Pokémon after every 2 Gyms, so I reach the E4 with my team of 5.
I will only hack in other games for the starter, or if necessary (For example, if I cannot get a second Pokémon until after the 4th Gym, I'll probably hack one in after the 2nd Gym)
Edit: UPDATE!
After defeating Clair, I needed a HM Slave for Whirlpool (And Waterfall for later) so I caught a level 19 Magikarp in Dragon's Den, and evolved it into Gyarados.
After obtaining the final of Johto's Gym Badges, I surfed East of New Bark Town, and went to face the Elite Four.
My team consisted of a level 36 Growlithe, a level 40 Machoke, a level 43 Dratini, a level 44 Rattata, and a level 49 Charmeleon. (I boxed the Gyarados as soon as I got there)
Suffice to say, I could not defeat the Elite Four.
I went backwards, and trained within Victory Road.
During my training, I stumbled across a level 32 Shiny Golbat. I caught him immediately with the Master Ball, and boxed him. (Let me off, it's a shiny!)
After my training, I had a level 38 Growlithe, a level 44 Machoke, a level 53 Dratini, a level 46 Rattata, and a level 65 Charmeleon.
I adopted a similar strategy to the Elite Four as I did to when I faced the E4 in my Pokémon Red runthrough (See previous post)
Dratini was able to defeat 2 of Lance's Dragonites however. He was more powerful than he seemed.
I defeated the Elite Four and Champion, and made my way to Kanto by boat.
Arriving in Kanto, I immediately went and defeated Lt. Surge, Sabruna, Erika, and then Janine, in that order.
My team after doing so was a level 44 Growlithe, a level 49 Machoke, a level 54 Dratini, a level 47 Rattata, and a level 68 Charmeleon.
I did the Power Plant quest, and defeated Misty. After all that, my Growlithe had become level 49.
Found Copycat's Lost Doll, and got the Magnet Train Pass from her, as I forgot to get the radio back in Johto. Doh! xD
Upon returning to Kanto, I immediately went and defeated Brock, and then Blaine.
My team after the Gyms was made of a level 52 Growlithe, a level 49 Rattata, a level 51 Machoke, a level 57 Dratini, and a level 68 Charmeleon.
Before facing Blue, I decided to get in a small amount of training.
When I faced and defeated Blue, my team consisted of a level 55 Growlithe, a level 53 Rattata, a level 54 Machoke, a level 59 Dratini, and a level 71 Charmeleon.
I went to Pallet Town, collected the ticket from Prof. Oak, and made my way towards Mt. Silver.
Upon reaching my final opponent, my team was a level 56 Growllithe, a level 53 Rattata, a level 55 Machoke, a level 60 Dratini, and a level 71 Charmeleon.
Charmeleon was able to defeat Red's Pikachu, but his Blastoise OHKOed every single member of my party.
I did some massive training outside Mt. Silver, by the PokéCenter, and made all 5 members of my party level 75.
Upon next facing Red, my Charmeleon was able to defeat his Pikachu with Flamethrower.
I then swapped to Rattata who was able to defeat his Blastoise with a mixture of Super Fang and Hyper Fang.
Growlithe faced off against Red's Espeon, using his own Flamethrower attack, but fainted before Espeon did. Charmeleon finished Espeon off in revenge for defeating a fellow Fire-type.
Dratini defeated Snorlax with a couple of DragonBreath attacks, and then finishing him with a Hyper Beam.
Machoke faced off against Charizard using Submission and Seismic Toss. Unfortunately, Machoke was not up to the task, so Rattata finished of Charizard with a Hyper Fang.
Red sent out his final Pokémon, a Venusaur, who promptly fell before the wrath of my Charmeleon's Flamethrower.
FINAL PARTY
Charmeleon lvl 75
Fire Spin
Flamethrower
Slash
Cut
Rattata lvl 75
Iron Tail
Super Fang
Quick Attack
Hyper Fang
Growlithe lvl 75
Flamethrower
Ember
Bite
Flame Wheel
Dratini lvl 75
Outrage
DragonBreath
Hyper Beam
Surf
Machoke lvl 75
Submission
Seismic Toss
Vital Throw
Karate Chop
I shall start Pokémon Ruby on Sunday, most likely.