Hot N Cold is still played on the radio... I haven't heard IKAG in ages and I MUCH prefer it to HNC.
I think Teenage Dream would come before Firework btw. California Gurls may have been her biggest smash(?), but it won't be remembered as her signature song, since it sounds like Ke$ha.
I remember I was listening to Katy's "Teenage Dream" in my car with my dad and after that I put "One Of the Boys" and "I Kissed a Girl" comes on and he is like "OOOH SHE IS THIS CHICK!", that made me choose IKAG!
I Kissed a Girl and California Gurls are the biggest hits so far in her career. Teenage Dream was bigger than Firework imo, and HotNCold was bigger than both of those.
