Recs.
Updated
Team Fortress 2 is a multi-platform, team-based, first-person shooter, multiplayer video game.
SpecsUpdate
Pros
Pro Multiple game modes allowing for great variation
TF2 has more than 10 game modes, plus variations on those, as well as community mods that offer a wide range of objective-based play. Classic game modes include Capture the Flag, Control Point, King of the Hill and Payload. There's also Mann vs. Machine, a co-operative game mode where you play against waves of AI controlled enemies.
Pro Hectic FPS gameplay created by 9 distinct classes and lots of varied items
TF2 has 9 playable classes - Scout, Soldier, Pyro, Demoman, Heavy, Engineer, Medic, Sniper and Spy. This allows for a range of playstyles. For example, the Heavy, starting with 300 health (going up to 450), wielding a machine gun and usually assisted by a Medic, will commonly be found on the front-lines soaking up lots of damage and pulling the enemy team's focus; at the same time the Engineer will try and avoid direct battle as much as possible, providing infrastructure (teleports, sentry, dispensers). Add to this hundreds of weapons for each class providing different stats and you have an impressive amount of variety in gameplay.
Pro Lots of customization options
You could customize just about anything. Although it's slightly limited (but still very broad) with the characters' items and weapons, which you can only get those available on TF2, the hud is REALLY customizable. Despite the Jungle Inferno update, which lessens the customization, it's still really broad. You can download tons of custom huds, and even make one yourself. Take ToonHud as an example, where you can make your own hud, ranging from a rainbow style hud, a classical style, or anything else.
Pro Includes Mann vs. Machine, a ridiculously fun co-op mode
Mann vs. Machine is a co-op mode in Team Fortress 2 that is comprised of gameplay in which 6 players team up to stop AI robots from deploying a bomb. Though not the central gameplay of Team Fortress 2, it is a mode that allows for co-op play to be enjoyed with the characters of the game.
Mann vs. Machine works quite well over LAN and is very fun to boot.
Pro Good VR support
To enable VR support, type -vr in console.
TF2 has 8 modes in which to control the game. They can be changed with the command vr_moveaim_mode in console. They offer choice in what combination of aiming and steering should be coupled to the rift and mouse and introduce the concept of dead zones - an area of the screen that controls differently when aiming or steering within its bounds than outside them.
Typing vr_calibration in console gives access to adjusting interpupillary distance (distance between eyes). You can get that information from an optician or use the calibration tool to help figure it out and set it there.
Calibration will help set accurate render point (camera position) and reduce nausea.
Cons
Con Free accounts are slightly limited
Free accounts do not get rare and cosmetic items nor as many storage slots for items.
Items are relevant as free accounts can only hold 50, while the game has much more than 50 pieces of equipment (that affect gameplay), let alone 50 weapons. While a premium account player can react to almost all situations with a counter item, with only 50 slots a newbie probably won't have or even be able to access it. A full inventory also means a free player will have to miss out or delete exclusive event items and cosmetics just to play the game as full as they can.
A free account is upgraded when any item is purchased with real money from the store.
Con Random critical hits add a significant luck element into the game and push certain types of players out
In most 'public' servers, an option called 'random crits' (short for 'random critical hits') exists by default. This allows a random percentage of your shots to multiply damage by 3 for a shot, and also remove the damage drop-off over range. This 'feature' gets increasingly more annoying as you get more experienced, as you will die more often than your opponent having x3 or more damage over you, actively making their experiences and wins less meaningful. Some classes are especially burnt by this. Medics don't use weapons often, Snipers only have secondary weapons and melees, and Spies only have their revolver (and most sidegrades of that revolver remove this ability entirely). Quickplay (a feature most newbies use to get a match) also disables these servers from appearing in the list, so there are very few 'nocrit' servers because many don't know they exist.