Spearow and Fearow - Recommended
Spearow is a Flying-type as aggressive as its anime debut. It has a strong Attack stat and high Speed. Its Defense is not poor either. It evolves into the long-beaked Fearow at level 20. Even if you don't plan to use a Spearow, I recommend catching one for an exclusive in-game trade later, which is helpful for completing your Pokédex.
Spearow, unlike Pidgey, learns Drill Peck. As I explained in the Pidgey review, Drill Peck is the most powerful and efficient Flying move in the game. Also, as an attacker, it makes even better use of Hyper Beam and Double-Edge than Pidgey does. Personally, there is another Flying-type that I recommend more than Spearow, but it is a very good choice.
Nidoran♀, Nidorina and Nidoqueen - Acceptable
Nidoran♀ is a defensive Poison-type. She can be hard to raise if you catch her now, but she evolves early and easily. She evolves into Nidorina at level 16, and again into Nidoqueen with the use of a Moon Stone. She gains a Ground subtype as a Nidoqueen, and, with it, an immunity to Electricity. Her Defense is her highest stat, but none of her stats are bad.
The moves she learns by leveling up are poor, but she can use a variety of TMs including Toxic. Her diversity is completed when she evolves into Nidoqueen and gains the all-powerful Earthquake.
She is fairly outdone by her counterpart Nidoking, who learns better moves by level up and has higher attacking stats.
Nidoran♂, Nidorino and Nidoking - Recommended
Nidoran♂ is an offensive Poison-type. As he evolves, he is another Pokémon fully capable of beating the game all by himself. He evolves into Nidorino at level 16, and again into Nidoking with the use of a Moon Stone. Like his counterpart, he gains a Ground subtype as a Nidoking.
At level 8, he learns Horn Attack, which, with 65 base power, is a lesser, but earlier Hyper Fang. As a Nidorino, at level 50, he learns Horn Drill, which has a dismal 30% accuracy and only works if the opposing Pokémon is slower than he is, but if it hits, is will knock out the opponent's Pokémon in a single hit. Please note that when you evolve most Pokémon by evolution stone, they do not learn any more moves by level up.
Nidoking has great Attack and good Special, but is weak to competitive staples Earthquake, Blizzard and Psychic. On the other hand, he can use all of those moves and more, including Surf, Thunder, Body Slam and Rock Slide.
Red Version players can save time by catching two Nidoran♂s and trading one of them for a Nidoran♀ later in the game. The trade is available in Blue Version as well, but Nidoran♀ is more common anyway.
When you're done, go back to Viridian City and head north onto Route 2.
