Welcome to Nico!!!
My .02
We owned an 05 G sedan and it was great!
I think when they went from the 05/06 to 07/08 they gave up a little sport for luxury, but it was well worth it imho.
I don't think you could go wrong with the 05/06 years or the newer G's..
However, the 07 has a weird gas pedal feel that they fixed in the 08.
The gas pedal tip-in makes smooth throttle modulation difficult.
We now have an 08 G35X and love it.
Did GREAT in the few snows we had. I would say it did better than any of the 4x4 SUV's I've owned in the past!! (88 Bronco II 4x4, 99 Exploder 4x4, 01 Pathy 4x4, 03 Pathy 4x4)
AND was much more fun to play with in an empty business park parking lot!!!!
Also, I've read that the X model is faster thru the twisties (wet AND dry) than the non-X.
Oh, and I'm in my late 40's.