Here is a tip or 2 when trying to find Gamera movies. There are so many versions out there w/many different prints

For VHS all Gamera titles are out of print.  The authentic ones that used to in print were the Celebrity Videos of Gamera, Gamera vs Barugon,Goas,Guiron and Zigra. These were all English dubbed full frame prints with a child doing a 1-3 minute into. Good quality for EP tapes. These were also the Sandy Frank versions as shown on MST3K with terrible English dubbing and water credit sequences. Another Video company- the one to really look for on ebay are Gamera videos from Neptune Media. They released UNCUT original versions of Gamera (AKA Giant Monster Gamera) Gamera vs Guiron & Gamera vs. Zigra. These were ALL letterboxed with superior English dubbing and superior print quality. These are also OOP, and are actually better prints then what is on the DVD market....

For DVD - Alpha Video has released Gamera, the old original English language,added American scenes & Gamera theme song, under the title Gammera the Invincible. The print is good, and is better than the celebrity video version in terms of English dubbing and print. No water credits sequence. Sinister Cinema used to and I think still carries this version on VHS and DVD-R, but Alpha has an authentic one & you can get it for 5.95 at oldies.com (their website). I found this version to be collectible. Alpha has also put out War of the Monsters(AIP version of Gamera vs Barugon) & Attack of the Monsters(AIP Guiron version), which are 2nd rate at best and Diamond put out a  rare but 3rd rate Gamera box set with AIP versions of Gamera,Destroy All Planets, Barugon,Monster X and there is also an ultimate Gamera collection out there, I think it is one disc with 2-3 movies. You can get it for really cheap but again it is really 3rd rate quality..which leads me to where to get the best classic Gamera DVD's: Retromedia. They have Return of the Giant Monsters(Gaos)Attack of the Monsters,Destroy All Planets(aka Gamera vs Virus) and Gamera vs Monster X. These are all AIP versions and for a few more dollars you get better prints for your Gamera movies than all these other companies. They are double features for the price of one ranging from 10-15.00 only.

There is also Supermonster Gamera which I dont think ever saw the light of VHS or DVD. This one is pretty bad since 90% is stock footage of all the other movies. And the dubbing is the PITS. The kids screaming "GumERA" as opposed to Gamera...ugh

ADV films put out great prints of the 1990s Gamera films all in a cool DVD box set which includes Guardian of the universe,Legion and Revenge of Iris. If it isnt from ADV don't buy it.

There are sellers who carry Japanese original versions of the Gamera films, but these are mainly bootlegs from laserdiscs or whatnot, so if you dont mind owning a non-authentic DVD or VHS of the original Japanese version, they are also available. I will say try not to spend too much since the movie isnt a really genuine one. And someday they may released here in the USA,just like Godzilla movies