1) Gigan - because the one from GFW made me a bigger fan of his
2) Hedorah - an underrated kaiju
3) Megalon - because he's one of my favorite kaijus, nobody's mentioned him yet, and he deserves some recognition.
4) Rodan - as long as its a version comparable to the bad ass looking 1956 Rodan
5) Biollante - an upgraded form of him