You will find great flight schools in the US. Cheap and good. Just don't put money up-front in any school. PAY AS YOU GO. Also, avoid big-name schools. They charge you lots of money- and in the end you get the same FAA license. In the end, one gives a crap if you went to flight safety or mom & pop's flying service.
The most important thing is- know the pilot certification requirements - do not fall for programs with tons of dual (with instructor) flying and stuff. For example: An instrument rating requires 50 hours of PIC cross-country time / 40 hours of actual or simulated instrument time / minimum of 15 hours with a CFII(most students will need more than that though) / 3 hours of check-ride prep. You can be pro-active and make sure that your 40 hours of instrument training are done inside cross-country flights. Also, get a safety pilot (check US regs to find about safety pilot), do some of your instrument training + cross country PIC without an instructor. You'll have more fun and save plenty of bucks.