M4 Sherman or as the German's used to call them the "Tommy Cooker"
It got its horrific nickname from early variants which when hit by German shells would often "brew up". This was due to a combination of obsolete armour, unprotected shells, and the highly flammable fuel stored inside.
In service from 1942 till the mid fifties in various incarnations almost 50,000 were built.
Wikipedia link for those who want to know more:
http://en.wikipedia.org/wiki/M4_Sherman