I don't really know, but here are some good ones.

Bowie Knife/Oar

All buyable melee weapons in the game as of this message. Bowie Knife has longer range, and enough damage to one-shot zombies until round twelve, found on both The Undead Nocturn and The Giant. Oar has an even longer range, can knock zombies back, and one-shots them until round 10, found on Lighthouse. Overall, Both are great for getting points in early game.

Box Weapons

Most weapons can and will carry you through the first 10 rounds. Some you shouldn't use are:

Any pistol

Sawed-off

Any Carbine

B93 Raffica

Kar98k

Panzerschrek

Wonder Weapons

All of these are decent, but some should be used more than others.

M2 Flamethrower (Round 1-12) (I know is not wonder weapon but come on)

Will get more use as a sidearm, Using its burning damage as a side.

M2 HOT 4 U (Round 1 - 24)

Pack-A-Punched M2 Flamethrower, Use is more effective. Sidearm can still work for the whole game.

Raygun (Round 1-14)

Good damage and AoE attack. Is probably the most useful wonder weapon.

Kyle's X2 Raygun (Round 1-30)

It's two Rayguns in one. It's almost a must-have.

Wunderwaffe DG-2 (Any Round)

Only in The Giant and One Window for now. This weapon becomes better the longer you live due to its infinite damage.

Wunderwaffe JO-3 (Any Round)

Better Wunderwaffe DG-2. Chains 24 zombies instead of 10. Ammo is still low, so buy Speed Cola.

Perks:

Perk-a-cola is all those drinks inside those vending machines around the map. Each gives you a useful effect.

Quick Revive: Halfs Revive Time, Grants Extra Life in Solo. (1500)/(500) (Solo)

Double Tap: Boosts Fire Rate by 33% (2000)

Juggernog: Sets health to 250, allowing you to take 5 hits until down. (2500)

Speed Cola: Doubles Reload Speed and Barrier Repair Speed (3000)

Mule Kick: Adds a temporary, 3rd Weapon Slot. Gets lost after getting downed. (4000)

Stamin-up: Boosts Walking Speed by 7% and Sprinting Speed by 20(?)% (No Machine, Obtained from Panzer Michael)

Tier List

S: Quick Revive, Juggernog, Speed Cola

A: Stamin-up

B: Double Tap

C: Mule Kick

That's all I have. Thank you for reading my work.

You forgot that double tap here is double tap 2.0, which also doubles damage of all bullet weapons

Edit: isn't the B93 already a pistol, why listing it when there's already the "Avoid using pistols" part?