Welcome to PokéCommunity! Register now and join one of the best fan communities on the 'net to talk Pokémon and more! We are not affiliated with The Pokémon Company or Nintendo.
I'm going with the classical one: Rattata. Raticate is actually an useful Pokemon, while the others are only good for HM Slaves. Oh, and of course Zigzagoon is also usefull for its Pickup (which does sadly suck after RS) ability, which makes it rank second.
Furret & Sentret all the way for me, simply because they are Gen II pokemon. And Gen II is my favourite Gen of all time. But if Pidgey was there I woul almost instantly go for him. I am not sure why, maybe just because I used to always have a Pigeot in my team in G/S/C and R/B/Y
Rattata because I've used him the most. Zigzagoon is useful for pickup, but that's all I've really done with it. I never used Bidoof, and it's been a while since I've even seen a sentret...
I'd agree with those who are saying Pidgey. Not only is Pidgey super-cute, but Pidgeot is a really good Pokemon for building a balanced team with, and I always use on in R/B/Y/G/S/C.
I freakin love zigzagoon. haha it has zig-zag in its name for heavens sake! But I also like sentret. I remember that it gives more exp points than hoothoot, rattata, and pidgey did when you defeat in in GCS