Cypress Hill are always played at any smoking sesh I have....They make some trippy ass songs, some of my favourites:
Hits from the bong
How I could just kill a man
Legalize(not really a song but its still sweet)
I want to get high
Dr.Greenthumb
Like a shot
When the shit goes down
Roll it up, light it up, smoke it up(It's been the first song ive listened to on Friday for months now...)