I had the G.I. Joes and Legos but my personal favorite where these bad boys.
These are AirFix 1:32 but as a kid in the US at least where I lived you could get the same molds in a big bag they where smaller though 1:35 roughly about 20 or 30 came in each bag.I had several bags worth or British,German,and Japanese and maybe one bag of Russians and I also had some Korean War era Chinese Peoples Army figures as well.
I used to dig extremely elaborate WWI style trench systems in the dirt and play with the soldiers in them.I would even have interlocking MG nests.
I also had US troops Vietnam style.
British
Japanese (mine where always puke green)
German
Russian
US Vietnam