Let's see....
I own (PSX) Armored Core,Armored Core Project Phantasm,Armored Core Master of Arena, (PS2) Armored Core 2, Armored Core 2 Another Age, Armored Core 3, Armored Core : Silent Line, Armored Core : Nexus, Armored Core : Nine Breaker, and Armored Core : Last Raven. Does that make me a fan of the series? :)
I grew up on Transformers, so I have a VERY soft spot for mech games, but add in the mech customization potential you get with the Armored Core series with weapon varieties and you can play the same game a bunch of ways. :)
Nobody is crazy enough to accuse me of being sane.