I defy you not to find these Borat clips funny....but there is a funnier character
[1] Baseball
http://www.youtube.com/watch?v=Ii-_cxDyChg
[2] Dating Service
http://www.youtube.com/watch?v=9d-qsnMPC0g
[3] Borat in the South - the first two minutes is priceless
http://www.youtube.com/watch?v=7YvxE7TpgbI
However, I must point out that I believe that another Ali G alter ego Bruno is in fact funnier than Borat or, at least, better at the general function of exposing other people's inadequacies or racism or whatever.
He poses as a presenter from Austrian Gay TV. He is less lovable a character than Borat hence the fact he isn't picked up on as much. Yet I think it provides some funny...while also quite shocking...moments.
If you don't have time to look through all of these, I would strongly advise looking at number 1, 2 or number 4 in particular.
[1] Bruno meets a pastor keen on 'converting gays'
http://www.youtube.com/watch?v=eW8_cz-6qro
[2] Bruno at Daytona Beach - "Gay means happy, right?"
http://www.youtube.com/watch?v=gyGQoPWY0ng
[3] Dancing
http://www.youtube.com/watch?v=aULGt39XC4c
[4] Alabama
http://www.youtube.com/watch?v=sNLojm0l84k
[5] Fashion Show [not great until the end]
http://www.youtube.com/watch?v=16lkQ0BkZoo
[6] LA [similar until the last interview]
http://www.youtube.com/watch?v=HCdvzh3CNNU
[7] Psychic [a little bit weird]
http://www.youtube.com/watch?v=qJWekfak_1c