Originally Posted by Nostalgia
Machamp's one of my favorite Pokemon so I often raised a Machop on my team. Another strategy I liked to use on Whitney was to use fast Pokemon with a sleep move (Gastly's a great choice) and once you put Miltank to sleep you switch to a stronger Pokemon to get some big hits in before it wakes up. Yeah Misty can a be a bit of a challenge, especially if you started with a Charmander. Her Starmie with Bubblebeam that would nearly always out-speed you could be a challenge from time to time.
Whitney was challenging. Morty too (Ghost Gym leader) with his Gengar with Shadow Ball and Dream Eater, Jasmine (Steel Gym leader) was easy most of time, just have a strong water type move or Pokemon to deal with Steelix and the two magnemite's were easy. Clair (Dragon gym leader) could be a challenge with her Kingdra sometimes.
I've used Machop, I just never liked picking that one up specifically to fight Whitney with. I never liked just picking up one type to fight a specific gym leader and then leave behind, I liked just picking the six out I wanted and going through all the way with them regardless of if they were good or not (though I make sure they're different types). And an HM-whore to switch out with the PC of course.
For some reason (aside from gen 1) I've always had trouble with Magnemites and Magnetons. I rarely wind up taking a fire-type so that probably has something to do with it. Now that they have that levitation thing too I can't even hit them with ground type attacks...
I haven't played any hacks myself, just some bootleg game called 'Pokemon Jade'. Which really isn't pokemon at all, just a poorly bootlegged game from Japan with a lot of nonsense dialogue. It's actually pretty great though.