Have a nice day!
* Acha din lo!
What's up?
*Ooper kia hai?
You're kidding!
*Tum bachcha bana rahay ho!
Don't kid me!
* Mera bachcha mat banaao!
Yo, baby! What's up?
* Beti Yo, ooper kia hai?
Cool man!
* Thandaa aadmi!
Don't mess with me, dude.
* Mere saath gandagee mat karo, ek hastee!
Check this out, man!
* Iskee chaanbeen karo, aadmi!
She's so fine!
* Woh itnee bedaagh hai!
Listen buddy, that chick's mine, okay!?
* Suno dost, woh choozaa mera hai, theek?
Are you nuts?
* Kia aap akhrot hain?

(no offense)
Son of a gun!
* Bachcha bandooq ka!
And the best one is.....
How do you do?
* Kaise kartay ho?
keep smiling...
Regards,
BUSHaRRaF