I like the Gurkha Brain Farts, too.
OK, seriously, I like most of the line. Just got some Titans, which I haven't tried yet (I have a cold and don't want to waste good stuff on feeling crappy) and I'm waiting on Grand Age and Beasts in a trade.
From what I've tried, I'd say the Legends and Doble Mads are best. I also like the Envoy, the cognac-infused types, and also KH's gold and symphony lines. I think until I've tried the others, hard to say I have a single favortite, but Legend, Doble M and KH gold are the tops so far. Whoops, almost forgot, I'd put the Centurian XX's up there, too. Give me any current Gurkha perfecto, and I'm a happy boy.