M5 Stuart
As far as light tanks go, the M5 Stuart is one of the worst. For those that are blissfully unaware, the M5 Stuart is a United States Tier 4 Light tank that offers tankers a completely useless gun to use. Instead of letting you aim and fire one shell at a time, this gun spurts out all five rounds at once.
The chances of hitting something square in the hull with all five rounds is so minimal, that when it does finally happen, the joy you receive from it will almost be worth the misery of missing and having to reload. Not to mention the M5 Stuart currently receives scout matchmaking, meaning it can see up to Tier 7 battles.
It used to have a derpgun, which made it playable, but it ended up being removed. Now, the M5 Stuart has one of the worst penetration values out of all Tier 4 tanks as well as awful alpha damage. The M5 Stuart is truly one of the worst tanks in World of Tanks.