Favorite band often depends on what you listened to during teen years and young adulthood. Black Sabbath and Led Zeppelin were my early favorites. My first rock concert in June 1973 was the last day of my sophomore year in high school. My buds and I took the bus to the Chicago International Amphitheater to see Deep Purple backed up by ZZ Topp. Saw a lot of classic rock bands in the 70's. Went to a lot of blues bars on Chicago's north side during the 80's. I've expanded my musical listening since then, and I won't prolong this post by listing all my faves.
I have to mention Pink Floyd, Beatles, Allman Brothers, Santana, Stevie Ray Vaughan, and my wife's favorite Robert Cray (we've seen him perform many times).
Really tough to name a single favorite, but the band for which I have the most affection is The Kinks.
Bet you didn't expect that after all the hard rock & blues I mentioned, but I adore The Kinks from their 1960's early hits into the 1980's. In my opinion Ray Davies ranks among the most brilliant songwriters of rock/pop music of the 20th century. My favorite albums are Arthur and Muswell Hillbillies. There were a couple albums in the the early-mid 70's in which he indulged his theatrical ambitions a bit much for my taste, but rarely have I been disappointed by Ray's wry wit, genuine feel for real people, or musical compositions. His brother Dave is a vastly underrated guitarist, though some recognize his influence from the heavy riff he pioneered in 1964 with "You Really Got Me" when he was 17 years old. Ray is two years older.