Tough question. As far as AFVs are concerned, I still have a very soft spot for my T3 Christie...
It was a project I did a few years back now, the inspiration coming from an article in a FSM issue. The author scratchbuilt a 1/35 model and I wanted to do something a bit more complicated, so I scaled down to 1/72 and opened up everything.
Everything, even the wheels are scratch. My pride was the radiator's fan, but it can barely be seen...
I now know of a few things that could be better on this model, but I still like looking at it. It's also the kit that got me 'noticed' at a show and started my 'career' as a professional modeler.