
Bagon is a good example of an all-round good pick. Its the first of a 3 stage line, meaning all its stats get doubled to reach 90/150/120/80/60/100. If it picks its HAs, it now gets Sheer Force + Overcoat + Moxie, making it broken on veil teams. It can also use all of Salamence's nice coverage without having that nasty dual ice weakness.

Magneton offers a lot of power. Evolving once, it reaches 75/90/147/180/105/105 stats, becoming a strong all-rounded wallbreaker and trapper. Note in this case, its stat growth is much better than magnemite despite magnemites being doubled.

Cosmoem is a monster tank. It can only evolve once, but it reaches monster stats of 64/43/195/43/195/55 and gets 3 amazing abils simultaneously with Sturdy, Shadow Shield and Full Metal Body. It also gets all the benefits of Lunala and Solgaleos movepools.

Eevee might not look that impressive with its 82/82/75/67/97/82 stats, but it might make up for it with an incredible array of abilities and moves. It could either run Volt Absorb, Flash Fire, Water Absorb, Adaptability, Synchronize etc at once, or go for Anticipation, Magic Bounce, Hydration, Guts etc to go for something more tricky but equally useful. It can run all kinds of moves like Leech Seed, Volt Switch, Scald, Foul Play, Knock Off and Wish.

Sneasel is a good example of a mon that just turns into a stat monster. It has stats of 82/142/82/52/112/172, strong, fast, and not particularly frail. A lot of the mons that received evos later on (Rhydon, Electabuzz, Porygon etc) turn into bulky deadly threats.