Was a FA* 200 4 macro... wonderful lens, I miss it. The fixed focal length of 200mm just wasn't really useful to me and I honestly don't do enough macro to justify keeping the lens. Now, I would have to say the Sigma EX 105 2.8 Macro (again, focal length not that useful, but macro capabilities are pretty nice) and Vivitar Series 1 105 2.5 (I have it in FD mount and have shot some film with it, but I really wish it were in K mount, then I'd definitely use it more).
But really, because of my LBA, I've tried and temporary owned quite a handful of really nice glass, but I always come back to my DA* 55 1.4- I use it for just about everything.