Starmie is very wonderful, and it has amazing coverage but I'm not much of a fan of its design. Ahh the gold old days of Pokemon Yellow.. solo run the whole game as a wee lad with Pikachu. Sure he would die 500 times but it was all worth it.
The reason I love Pikachu isn't just Pokemon Yellow, but the first generation in general, as well as the sixth generation, the anime, and some ROM hacks. Pikachu is a great early-game Pokemon, and if it evolves into Raichu, it can hold its own against the Elite Four, especially if they use Flying types like Pidgeot and Gyarados.
Alakazam is also a great Pokemon, though. However, I prefer Starmie, because it gets Surf, Ice Beam, and Thunderbolt. Those moves have typing coverage that I find important on a serious team.