Probably the most important lesson I learned from my interior design internship while still in school is to use authentic materials and not materials that are trying to mimic other more expensive materials. Don't fake it. If you want granite, then use real granite instead of a man made product pretending to be granite. If you want wood, then use real wood instead of laminate or other lesser products trying to pass themselves off as wood. Feel free to use lesser price materials that are authentic to themselves, but trying to pass something off as another material is just as bad as owning a knock-off handbag.
I would say that there are occasionally exceptions to the rule. One exception that I find acceptable is to use wood looking vinyl plank flooring in a basement since you can't put wood in a basement. Another way to get the richness of wood in a wet or high traffic area is to use a deep colored natural stone like slate.
For countertops, not everyone wants a natural stone since it can stain. Instead of natural stone, you can use a man made material that does not try to mimic the look of granite or marble. Whoever built my house put in cultured marble in the bathrooms - which is perfectly acceptable. The problem is that instead of using plain white cultured marble that looks like cultured marble, they installed white cultured marble with gray veining that attempts to look like real marble but fails miserably and looks horrible.
Homes built in the 1980's often have fake marble tile on the entryway floor with real marble used as a fireplace surround (since it only uses a few tiles they often upgrade that area). Even today, the real marble looks great but the fake marble is obviously fake and looks really bad. Investing a few more dollars into the real thing costs a bit more up front, but will continue to look good for many more years that man made products trying to fake it.