Led Zeppelin, Pink Floyd, Steely Dan, Stones, Beatles, Police, Yes, then Emerson, Lake & Palmer in that order.
I enjoy all kinds of music, but Pantera ushered in the metal/hardrock sound that I like the most, back when I was in high school.
The Boston Pops Orchestra. A few teenagers with electric guitars and a set of drums do not constitute a band. A quartet, maybe but not a band.
Selecting one band is difficult to do without asking which category of music. I've enjoyed bands of many categories in my 57 years. Here's my band list as I couldn't select just one. Led Zeppelin - Queen - Black Sabbath - Beatles - Scorpions - Van Halen - Motley Crue - Momma's & Poppa's - The Temptations - The Commodores
Overall, I'd vote for The Beatles. Of currently active bands, Chris Robinson Brotherhood is at the top of my list.
Doors for my youth. Rolling Stones for hanging around so many years. But I won't pick best, too hard a choice. All great.