(taken from Anthony Burch's article on playing a spy)
Today I am here to talk about evil. The evil of Valve's spy in Team Fortress two.
Being a semi new player, I am often frustrated by the evil doing of a clever spy (yes, they're clever. i'm sure as hell not as good as them). I enjoy playing as a good pyro, sniper, scout, or medic. The Pyro as anyone who has played can tell you, has minimal trouble with a spy, the other three classes is where the destruction ensues.
The Sniper: A good spy will sneak up right behind you and just like that it's over. Of course no one has your back (until you find the razorback) so a revenge kill is not even made. I found the razorback recently though. tired of getting backstabbed while zoomed in or pulling back the bow, i equipped it. What does valve do to "Balance" this? they give the spy the Ambassador, it does less damage, but grants critical headshots. I'm zoomed it waiting on my prey, safe with the razorback, then, headshot, on me, point blank, from a spy. Needless to say anyone within a 1 mile radius hears me scream WTF, and no, it isn't the acronym.
The scout:... you know in retrospect, not much trouble with spys as a scout.
The Medic: The medic is essential, especially in those no respawn overtime moments, but being a medic means watching someone elses (i.e. Heavy, demo, soldier, pyro) back, and no one to watch yours. I've never healed an enemy spy (to my knowledge) but i'm always healing only to be backstabbed. It gets a bit ridiculous.
Refute: Of course i can be caught playing as a spy on some occasions. when i get tired of being shot by a sniper, i'll pull out my handy knife and cloak and get ready to go stabby stab upon their backs. and i must tell you. As much as i despise the spy for all his evil. all his brilliant, tactical evil. I envy him. Not only does he wear a nice suit to battle, a ski mask, and carry a revolver (like james bond). He also destroys things, pretends to work for the enemy (sometimes like bond) and carries a badass one hit kill knife (if done correctly... unlike james bond). I'll tell you... when you get that payback kill and go for the double only to be lit on fire. Its pure bliss, pure evil bliss. The spy goes out backstabbing the enemy in a blaze of glory due to a spy check.
Do the wrong thing, and play spy, humor your dark side, and in the meantime. i'll play pyro.