Bombay first followed a close second to Hendricks Hic!
Tanquery 10 is my gin of choice; traditional martini style, grapefruit twist. As far as I know (it's been a while since the Tanq rep came into my bar), Tanq 10 is the only mass produced gin that uses fresh, hand picked and hand cut botanicals.
If I'm just having gin and tonics, I'm very happy with Bombay (with lime) or hendricks (with cucumber).
Tanq 10 is fantastic. I like the grapefruit twist idea - nice one!