At the moment and for the long time my top 5 bands of all time is this. 3-5 have often rotated but in terms of impact on me as a person I have them lined up.
1. (Favourite band ever) AC/DC. Why? The consistent habit they have of making catchy memorable rock anthems even the lesser known material. Love their discography of both eras too. Loved this band since I was a little kid.
2. Megadeth. The band to get me into heavy metal properly. Another band to have a ton of memorable songs and riffs alone. Mustaine has had some awesome musicians by his side and has himself written some of the best in metal.
3. Metallica. A band with a lot of songs to help me through tough times and even in the happier times. Their 90s material has grown on me more. I still hate St Anger and Lulu but otherwise each project has had something I love. 80s albums speak for themselves but songs like The Unforgiven II speak out to me a lot too. Sentimental value for me this band.
4. Cannibal Corpse. When on a bad day this bands consistent ability to pick me up with its violent style of death metal is why I never tire of these guys.
5. Epica or Tarja Era Nightwish. Tied here because Epica and the Tarja era Nightwish both have music styles that appeal emotionally like I said about Metallica. Both set a nice atmosphere in their music and I enjoy both of them to the extent of being on the list.
Close behind are bands like Judas Priest, Morbid Angel, Pantera, Katatonia and Opeth.