I think Gabe newell is a memeber to GB so maybe he will take a look at this and get some ideas. 

Demoman:   Cluster-bomb - fires a pipe bomb that explodes( doing only half the damage of a normal pipe bomb)  into 10 little bombs that cover a large area and then explode (doing 5 damage per bomb) 
                                                     Cluster-bombs have a faster detonation then normal pipe bombs
                       
                         Unstable sticky bombs -  these look just like normal sticky bombs but if they are shot or stepped on they expload, they do 25% less damage but have 25% larger explosion area. no crits with this bomb
                       
                         The good stuff -  This bottle of the good stuff gives you 25 health every time you taunt with it.  If you break it over someones head though you will be upset. 

Engineer:  Pneumatic wrench -  Builds faster, Heals gadgets faster, removes sappers faster, doesn't do much damage if any
                    
                     Remote control robot bomb -   This robot is small and fast (a little slower then the scout)  you can detonate it at any time.  As you control it you are defenceless takes the spot of the pistol

Scout:  Stun baton -  Stuns anything you hit for 2 sec, but has a slow recharge maybe like 10 sec so you can't abuse it. 
             
               Light SMG -   something like what the sniper has, would replace the pistol
             
               Solidshot -     shoots a solid shot that does better damage at long range with no scatter effect

Soldier:  Rad rocket-  Fires a radiation rocket that does half the damage of a normal rocket but leave behind a cloud of radiation(last 5 sec) enimes that enters the cloud will be be irradiated for 5 sec, 
                                         when irradiated you move slower and take damage over time(damage = to 25% a normal rocket hit)  You can not get crits with this rocket
               
                Semi Automatic shotgun -  Fires faster and quick clip reload.  does 25% less damage

Sniper :  Semi Automatic sniper rifle -  no longer need to leave the scoop sight but this gun is far weaker then the normal sniper rifle doing 50% less.  damage head shots are still automatic crits
                
                 Boomerang -  Just like the one you used in the outback.  left click swings it like a melee weapon, right click trows it (the longer you hold down the right mouse button the farther it goes)
               
                 Camouflage -  A bush for outdoors and a steal-drum for indoors.  your movement speed is half that of crouched movement

Spy :        57 magnum Revolver  -  This baby has a lot of kick!  50% more damage then the revolver only has 5 shots before you have to reload.  reload is slower then normal revolver
                
                 Ethanol -  maybe you don't want to kill that guy... just yet.  Replacing the knife you can knock out someone for 5 sec and not loss your disguise.  
                                     The victim lays on the floor like if he was dead unable to do anything if he is harmed in anyway he returns to normal.
                
                 Booby trap -  Replace a sapper with a booby trap. It looks just like a sapper but  itdoesn't stop the engineers gadgets from working but if he goes to repair them (or remove the trap)... BOOM!! 
                                         When the booby trap explodes has the same damage and effect as a sticky bomb, any other booby trapped buildings with also go off if they are hit buy the explosion.

I want the spy to have a silenced pistol. Mostly because... a spy with a loud ass revolver doesn't seem like much of a spy.

Bass said:

"I want the spy to have a silenced pistol. Mostly because... a spy with a loud ass revolver doesn't seem like much of a spy."

true,  they could give him some kind of silenced pistol or SMG