All of them are snipers and they range from annoying to really stupid.

The Russian ones, the [VALVE] MLP stupid bots, [VALVE]n-word killer, the [VALVE] furry etc etc. They are basically the same stuff.
They are wearing the Pyro vision goggles, the Gibus , MONOCULUS! , The Skull Island Topper and the Frontline Field Recorder (or being straight up default).
These bots are usually equipped with the normal sniper or the Machina
They usually like to shoot when they are facing you with their backs
Their natural habitat are the Casual servers

For the scout you will need to be aware of your surroundings so you don't get aimbot'ed.
As the weapons of choice are the following:

Primary:
The Standard Scattergun , Force-a-Nature , Back Scatter and the Soda Popper.

Secondary: Bonk! Atomic Punch , Crit-a-Cola and the Mad Milk

Melee: Fan O'War , Sandman , Frying Pan and the Necro Smasher

Note: never try to be a trollgier and these bots

Primary:
Rocket Launcher , Direct Hit , Black Box and the Cow Mangler 5000

Secondary: Shotgun , Buff Banner , Battalion's Backup , Concheror and Panic Attack

Melee: Escape Plan , Half-Zatoichi , Frying Pan or the Shovel

pyro.

Primary:
Flamethrower , Backburner , Degreaser and the Phlogistinator

Secondary: Flare Gun , Detonator and Panic Attack

Melee: Fire Axe , Frying Pan , Axtinguisher , Powerjack , Sharpened Volcano Fragment and the Neon Annihilator

Note: As Demoman you will need some experience before knowing what are you doing.

Primary:
Grenade Launcher , Loch-n-Load , Bootlegger , Iron Bomber and the Loose Cannon

Secondary: Splendid Screen , Chargin' Targe , Tide Turner , Stickybomb Launcher , Quickiebomb Launcher and the Scottish Resistance

Melee: Frying Pan , Horseless Headless Horsemann's Headtaker , Eyelander , Scotsman's Stovepipe and the Half-Zatoichi

As Heavy it is the easiest class to kill bots because of the high HP and damage.

Primary:
Minigun , Brass Beast and the Tomislav

Secondary: Fishcake , Sandvich , Dalokohs chocolate , Panic Attack and Family Business

Melee: Fists , Frying Pan , Killing Gloves of Boxing (KGB) , Fists of Steel and Holiday Punch

As Engineer you can help your team by placing Dispensers or Sentry's in strategic positions

Primary:
Frontier Justice , Widowmaker and the Panic Attack

Secondary: Short Circuit and Wrangler

Melee: Wrench , Southern Hospitality , Gunslinger and the Eureka Effect

Medic can buff his team but sadly they are the first targets when encountering bots.

Primary:
Crusader's Crossbow or Blutsauger

Secondary: Medi Gun , Quick-Fix , Vaccinator and the Kritzkrieg

Melee: Übersaw , Amputator and the Frying Pan

Playing as Sniper VS a Sniper bot is like playing "The World Hardest Game"

Primary:
Sniper Rifle (or the AWPer Hand if you are more cooler) , Bazaar Bargain , Machina , Sydney Sleeper and the Classic

Secondary: Submachine Gun , Jarate and the Cozy Camper

Melee: Frying Pan , Tribalman's Shiv and the Shahanshah

Don't try and DO NOT even try to go invisible and try to backstab them, are you crazy?

Primary:
Revolver (or Big Kill if you're a absolute swagger) , Ambassador , Diamondback and the Enforcer

Secondary PDA: Dead Ringer

Melee: Knife , Golden Frying Pan ( ͡° ͜ʖ ͡°)