Wherever you like. Go on YouTube and type in something like "San
Andreas Stunting" and you'll get a nice long list of videos featuring
some amazing stunts that will give you a few ideas.

My personal favourite places are Los Santos and San Andreas. There are
enough pieces of street furniture to pull off some great stunts.

You could also use any of the 70 unique stunt jumps to pull off some of
your own too; much of the fun that can be had in all the GTA games is
experimenting with the landscape.

I can recommend an NRG500 motorbike or any of the fast sports cars
equipped with nitrous. The Ford GT lookalike called a Bullett is good,
as are a Banshee, Cheetah or Infernus.

Cheers,
Rob

"Do sugar cubes have dots or is that a dice I just put in my tea?"

To the world you are somebody, but to somebody you are the world.