pretty good if you have real friends.
i say real friends because internet friends are not you're friends, they're people who know they can beat you easily so they keep you close so they can get points off you. however, lan games are pretty fun. i used to watch a couple friends play all the time so finally i bit the bullet and just bought the damn game. i was entertained for about a month. i put up with all the jabbering and stupidity that is the internet community, and sometimes i had a real good time. other times, i would be frustratingly angry at the fact that the turrets are placed oh-so well.
this game is in no way a bad game. it does what it does, and it does it well. i liked pretty much all the classes (except spy, i suck at spy) but i had a special place in me cold empty chest for the scout and demoman. each class fills a position and this makes it quite easy to jump into the game. for instance, if you start with sniper, you know youre gonna be sniping, hence, sniper. engineer, you know youre gonna be dropping dispensers and turrets nonstop. its a quick game to get into, and thats one of the reasons i found it appealing. also, the humorous undertone made me crank up the sound alot more often then not. one thing that kept me playing for a while was the acheivments. some of them were a challenge to pull off, while others were good simple fun (set 5 enemies on fire in 3 seconds, or something of the like). the unlockable weapons add a nice variety to the game. the higher up weapons always offer a pro and con. the scouts new baseball bat fires a baseball that can stun enemies, however the scout loses the double jump. this is only one example but it adds a small amount of welcomed customization. im looking forward to the next update.
the game has a huge modding community (HL2 engine is only second to unreal tournement i beleive) so i reccomend playing some modded maps for some extra fun. surf maps are cool for a little while, but takes a little getting used to. baloon race and wacky races are my favourite, however having to bind the "use" action to a key is something i think valve should have done themselves.
in terms of things i didnt like, well there was just one that ruined it for me. that would be the annoying buggers with microphones. obviously its not just TF2 that has this problem, but at least when im playing L4D they have something constructive to add. in TF2 they just kind of jabber and sing and talk about stupid things.
the only other thing that makes me just a bit mad is the amount of time between each update. TOO LOOOOOONG! they give you these cool new items and say "look forward to the next update!" then 5 months later they go "hey lookie what we did!" and i sit there going "do i still have tf2 on my computer?".
other then that, this game is fun. a nice team strategy game, and if you can find a team with mics that are actually good at planning and arent singing simpsons tunes over the internet, then some decent amount of pwnage can occur.