For me it began with "Mrs. Frisby and the Rats from NIMH," which led to "From the Mixed-Up Files of Mrs. Basil E. Frankweiler," which in turn led to "A Wrinkle in Time," and finally to the realization that books with the gold Newberry Award Winner star might be worth reading.
Gregory McDonald's "Fletch" and Harry Kemelman's "Friday the Rabbi Slept Late" opened up mysteries for me. Puzo's "Fools Die," which had its faults, is a great story about a writer. Finally I will throw in Hunter S. Thompson's "Fear and Loathing on the Campaign Trail '72."
Bestsellers i admire: RA Salvatore for the Drizzt series,esp the first few volumes. Terry Brooks, Margaret Weis, Sophie Kinsella, recently James Barclay a Uk author. Mostly fantasy about fae and elves, which are awesome.
many ya fiction are also cool like Holly Black and new authors that don't write sappy romances.
Booth Tarkington has remained a perennial favorite.