"You, yes, you! You are dead!"
(these groups are to see which class is most popular.)
As the class name implies, Heavies are the heaviest class in Team Fortress 2, boasting the highest health max, the biggest gun, and the slowest footspeed. Their firepower is very impressive, able to quickly mow down just about anything but an opponent Heavy in seconds, and able to take on large numbers of enemies at once up to a reasonably long range and wide cone of fire. However, revving up and shooting the Minigun brings their already-unimpressive speed to a snail's pace, making them an open (and large) target for any enemy outside their range of fire - especially enemy Snipers.
Making an excellent teammate for a Medic, and being far more effective with allies of any class going alongside them to draw fire, Heavies may seem all-imposing even alone but as the name of the game suggests, they truly shine in a well coordinated team. They may not be the most complicated class, but no good team would be complete without one.
Heavies are an opposite to the quick scout, him being very fast but with low health and not very damaging weapons, while you are very slow, but can soak up huge amounts of bullets and can send a volley of your own.
The Heavy is also arguably the face of Team Fortress 2, appearing the most prominently in the box art, concept images and promotional materials as well as starring in the very first Meet the Team video and prominently in all following videos (usually ending up either maimed or killed).

