Yeah as everybody else said, It's worth the money ( it's not even expensive!). I'd say get it! I love TF2 I used to play it a lot but I got my xbox 360 back so I'm on that more often.
But yeah, get it! The graphics make the game unique and I love you're able to choose between classes and find or craft items for all the 9 classes.
I'm not sure if you know what classes are available so I'll list them anyway:
Offense:
1. Scout
2. Soldier
3. Pyro
Defense:
4. Demoman
5. Heavy
6. Engineer
Support:
7. Medic
8. Sniper
9. Spy
I hope you make the right choice!
Edit:I've only played TF2 for 76 hours. I have it for about.. 9 months orso. I had another Steam account with TF2 on it but I got banned ( not allowed to discuss why I got banned on the forums ) I think I played a lot of tf2 on that account.