For me I think it has to be Snakey Shaker. Other tracks like Deranger have more going on but the simple yet beautiful and urgent acid lines of Snakey Shaker are surely what you get when you distill Simon's talent into its purest, most concentrated form. That square wavey sounding choir of synthesized voices is so cool as well!
It helps that I had not really heard any Goa trance (with the possible exception of a B side released under Paul Oakenfold's Perfecto Allstarz moniker) before buying Lone Deranger on sight, so the second track was by far the hardest, trippiest thing I had ever heard and left a lasting impression.
After that, I would probably say Horrogram for the great melody, followed by Deranger and LSD.