I really wonder which type of cameras are using in American TV series like Lost, 24 or CSI.

Are they using HD cameras? or 35mm?
And how they can manage filmlook in 60hz TV's?

Those shows are shot on 35mm film. They then go through a telecine process which places the 24P into a 60i stream with a 3:2 motion cadence. To understand 3:2 cadence, see the link below and scroll down to where you see "24P Standard" in bold.

www.adamwilt.com/24p

-gb-