Quad-eye Moto, and Klawz Battsky are two of my faves, man. Burp and bake, and Jawbreaker are up there too.
I don't really find the RAMMs "sexy". I used to have several, but sold/traded all of them, and just kept my regular figs, and mutants.
I'm not big on metallic figs, and, at the time, figured that there was no hope of me ever collecting all the figs from this line anyway, so I decided to just keep the regular figs, since those are the ones that I really like.
I think I may try to acquire some of the c-series figs now though, since it appears that they are becoming somewhat easier to acquire these days.
By "easier", I mean people aren't asking completely stupid money for them.
As far as my approach, I haven't really acquired any FOA stuff since the market went stupid. I used to scour ebay for mislisted stuff, and tried to trade with any LRG members who might have any that they were willing to trade.