Alakazam

With the highest Special Attack in GSC OU, ultra high Speed, and STAB Psychic, Alakazam is well positioned to take advantage of the popular offensive Poison- and Fighting-type Pokemon such as Gengar, Nidoking, and Machamp and severely threaten a broad swath of the metagame. Compared to Espeon, which has Growth and Baton Pass, Alakazam has Dynamic Punch, which allows it to use a mixed set, and Encore to stop setup Pokemon. Its Speed advantage over almost all other Pokemon makes it one of the best late-game cleaners and ensures that other fast Pokemon like Raikou and Gengar can't threaten it with Thunder or Explosion without taking a heavy hit first.

However, Alakazam faces one very large problem. Snorlax, as well as other specially bulky Pokemon such as Blissey and Dark-type Pokemon such as Tyranitar, can make it very difficult for Alakazam to deal lasting damage to the opposing team if they are not first weakened or removed by its teammates. Alakazam does have Dynamic Punch in its arsenal to give it a fighting chance at breaching these Pokemon, but it is unreliable due to its poor accuracy. In addition, status effects, especially paralysis from Pokemon such as Exeggutor, will compromise its potential. Furthermore, compared to Jynx, a much more common offensive Psychic-type, Alakazam has better defensive properties and unique coverage options, but it lacks Lovely Kiss and the ability that Jynx has to 2HKO Zapdos with STAB Ice Beam.