Personally I'd never buy a Logitech "G" keyboard. But people seem to like them.
I am using
MS SideWinder X6 for the past 1.5 years and have nothing but praises to say about it. The slightly different key layout takes few days of getting used to but in the end it is a very nice keyboard. A bit on the 'old school' side, with modern features - best of both worlds, at least for me.
And the removable NUMpad is a great feature.