Watch Meet the Sniper: http://www.youtube.com/watch?v=PyNuriXG3BQ or Meet the Demo Man: http://www.youtube.com/watch?v=rxps--huGKY&feature=relmf...
Listen to some of the Demo Man sounds: http://wiki.teamfortress.com/wiki/Demoman_responses . The game is really well done, you have funny characters to pick from.
- Demo Man - One-eyed drunk cyclops who is a black scottish patriot.
- Sniper - Talks like Michael Caine did in the 60's. Throws "jarate" at people.
- Engineer - Texas redneck with tech know-how.
and more...
I really love TF2 and play it a lot, so should you!