Pikachu for Bottom.
Pikachu - Bottom Tier
: Horrid. In GS, he's found only on Route 2. In Crystal, however, not only is he found on Route 2, but also at the Celadon Game Corner. Better, but still really bad.
: Decent speed, everything else is blow average.
: Above average. Other than Electric and Normal attacks, he can also make use of some TMs such as Rollout or DynamicPunch, but it's not recommended.
: Pure Electric. Weak to ground, resisits itself and Flying, but Pikachu will crumple under any decently powered STAB move anyway.
: Base 50 Atk and Base 55 Sp. Atk isn't going to get him very far, unless you trade him from Yellow and let him keep the Light Ball, which is unlikely.
: Without a copious amount of grinding, Pikachu won't be contibuting anything significant in any major battles after you catch him.
: You could snag a Thunder Stone and evolve him, but GSC made it very hard to get your hands on one.