final wars is massive free for all monster melee movie.. basically godzilla fights pretty much all the monsters he ever fought. not all of them, but most...
a good series to go with is the toho co... sorry if they do all of them, im not that informed on godzilla.
and the american godzilla.. u'll have to watch that one first. its a must see to fully appreciate this movie.. at least... a small part of it anyhow.
i have the toho series that include the biolante the destroyah the space godzilla and such.. i dont know if they appear in other series... if they do sorry.
um.. i would watch the orginial godzilla movie, the black and white one, then the 1985 just to get a good idea, then the wonderful (gawdawfulestpileofcrappiestgiantlizardmovieever...) american godzilla move, and then any series really, the final wars doesnt hint to any specific series that i can tell.
ok i just looked at my vhs's... they didnt have a series name but biolante vhs was released in 1989... dont know if that helps you out or not but i hope it does. good luck dude, maybe one of the big G experts can help you out. pretty sure i just confused you.