personally, i think Magikarp is most useless cause if you don't have tons of Rare Candies on hand, it doesn't evolve. I have a Magikarp in my Fire Red and I beat the game and my Magikarp never evolved so its a waste of time trying to catch it and evolve it into a Gyardos. That's why you should trade it to and emerald, sapphire, ruby, leafgreen or something like that, acsess Pal Park in Diamond/pearl and send the Magikarp to your DS game and level it up and use it there. That's what I did.
And Bidoof has some great uses. It can learn the following HM moves:
Rock Smash
Rock Climb
Cut
Surf
Waterfall
Strength
maybe more, but that's all I can think of. And Wurmple evolves into Silcoon/Cascoon and i thought Cascoon/Silcoon are really rare cause when I encountered one in Petalburg woods in my Emerald, the screen was diffrent that normal so seemed rare.
Maybe Rattata is useless, but not as useless as Magikarp!
And last but not least, Caterpie. That has to be my fave bug pokemon in Kanto. I love its big eyes and it evolves into Butterfree. So if you like that kinda pokemon, it might not be useless...