Tire preference is a very personal thing and I've also found that what might be reported as a great performing tire on one vehicle ends up being very mediocre on another manufacturer's similar vehicle. Yeah ... I know, there's nothing similar to a G-class.
In any event, I just thought I'd share my G-class tire experiences ....
I've been running the newer Yokohama Geolandar A/T G015 265/65R18 tires on my 2011 G550 for 2 years now. Also available in LT sizes with greater tread depth and beefier sidewalls.
I'd have to say that this updated Geolandar tire is as close to an all-weather/all surface tire as I've been able to find. They are noticeably better on ice than the Nokian WRG3 SUV all-weather tire and far better in the dry, wet, snow and on gravel. On par with other A/T tires in mud (IOW not great).
A tire I see no mention of here is the venerable Hankook Dynapro MT RT03 which I run on my 1991 250GD Wolf. Unlike other dedicated mud tires, they're not hard like hockey pucks when the air temperature dips below freezing, don't wander at highway speeds and are very quiet for a mud tire. The rubber compound is softer than other mud tires which will likely mean shorter tire life. And they look the part of a somewhat "military" tire so perfect for a Wolf.