If we're talking T2 it's any figure in any scale that has the sunglasses head.
I for one am glad to have the very first 1:10 scale Pescadero Escape figure, the one with statue legs. Just a solid figure that holds up well enough. You had the 12'' version of it. The closest you can get now short of paying high for that original figure is the Ultimate release - but that has a grey T-shirt. Oh wait, there's also the 25th anniversary Rosebox figure - that had a black T-shirt to go with the Rosebox but I think it's also relatively scarce compared to the Ultimate, which has seen a number of rereleases.
The 1:4 scale figure gives you removeable sunglasses, the grey T-shirt, gloved hands and the Cyberdyne gear - I really love the grenade bandolier on that - the 'nades are appropriately big and standout.
For T1 I have a particular fondness again for the original statue-legged Tech Noir release but using the better painted heads from the later and more commonly available Ultimate figure. The Ultimate is good but I feel like the legs are a bit slimmed and shorter and I've never quite liked that personally. Could be more accurate for all I know but for T1 when Arnie was bigger I err on the side of beefier legs which I feel they were on the original Tech Noir figure from way back.
The T2 and T1 lines did not get the fullest range of improvements in articulation that would be seen in the Dark Fate figure like double-jointed elbows. Articulated Knees and hips were where they ended up and now it seems like Terminator is over and done for NECA so you should expect single jointed elbows on whatever you get.