This is a very difficult task, mainly because there are many bands that were very talented and there were many bands that shaped my perception of what music really meant to me and then there was the drugs I was taking at the time all this was going on.
I can list the top 5 bands that shaped my early musical period:
The Rolling Stones
Electric Light Orchestra
The Moody Blues
I can list the top 5 bands that shaped my middle musical period:
Alan Parsons Project
I can list the top 5 bands that I like now:
The Gotan Project
The last ones are just off the top of my head and are by no means the best top 5 of the bands I like now, but I do like all those bands a lot. I have a station created on Pandora that has those and many more and it is my go to station that I listen to most when I am in one of my cars.