Reddit mentions of The ToHo Godzilla Collection - Volumes 1 & 2 (13-Movie Collection)

Assuming you're in the US, there isn't one. It's a massive cluster fuck when it comes to the rights. Some of the movies are out of print, some are only on DVD.

I'd say the two "best" boxsets you can currently buy are going to be either the Toho Collection which has most of the Heisei-era films (Missing Biolante and Returns/1985) and all of the Millennium films or the out of print Godzilla Collection which has most of the Showa-Era films in it.

I have every movie released and it sucks trying to find what you're looking for stateside. /r/godzilla might have more suggestions though.

While I sadly can't help with the Showa movie collection, this set on Amazon contains every Heisei and Millennium Godzilla movie, with the sole expections being Godzilla vs. Biollante and Rebirth of Mothra three.

https://www.amazon.com/ToHo-Godzilla-Collection-Volumes/dp/B01JZKXCO6/ref=asc_df_B01JZKXCO6/?tag=hyprod-20&linkCode=df0&hvadid=312241836172&hvpos=1o1&hvnetw=g&hvrand=842427918647232425&hvpone=&hvptwo=&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=9032363&hvtargid=pla-404432097036&psc=1

If you want the best picture quality, absolutely go for Blu-ray. If DVD is good enough for you, then by all means go for it -- it's generally cheaper anyway. Some films are available in multi-format combo packs; if you're fine with DVD for now but might switch to Blu later, then it might make sense to grab those.

The rights are definitely all over the place. Here's a handy breakdown of who owns what. Those Blu-ray double features (plus Godzilla 2000) cover the Toho-produced films from the '90s and '00s.

Criterion has released an excellent DVD and Blu-ray of the original Godzilla from 1954, which is an absolute must. Other than that, as far as we know, they currently own and are apparently working on discs of the rest of the Showa Godzilla series except for King Kong vs. Godzilla, Godzilla vs. the Sea Monster, Godzilla vs. Hedorah, and Godzilla vs. Gigan. (They also own Rodan and War of the Gargantuas; no word on whether those specifically will be released on disc.) We don't yet have release dates or official announcements for any of these films, and I personally wouldn't expect to hear anything before February, which is when their May 2019 releases will be announced.

If you just want to see as many of the films as possible and worry about the best available release of a given film later, here's a shopping list:

• Classic Media's Godzilla Collection box set. A good chunk of the Showa series in Japanese with subs and dubbed. OOP, but can probably be found cheaper than all the individual releases.
  
• Both volumes of Sony's Toho Godzilla Collection. Covers the '90s-'00s Japanese films, plus Rebirth of Mothra I and II. Note that these are reissues of older discs, so some are dub-only and/or pan and scan.
  
• Godzilla Stomp Box, containing Godzilla vs. Megalon and Destroy All Monsters.
  
• King Kong vs. Godzilla, Godzilla vs. the Sea Monster, Godzilla vs. Hedorah, Godzilla vs. Gigan, The Return of Godzilla, Godzilla vs. Biollante (OOP), the 1998 and 2014 American films, and Shin Godzilla are all available in standalone releases.
  
• The anime films are on Netflix. No word on whether these will get physical releases.
  
  Of course, aside from physical media, there are always streaming options of varying legality as well as bootleg discs, but I doubt the mods would take too kindly to my posting specifics about those here.
  
  Hope this helps!

Starting with original and (at least attempting to) making your way through the series by release order is probably simplest way to go about it.

There's also a collection set that carries most of the Heisei era and all of the Millennium era films for around $50, which could be a good starting point.

There's also streaming options, though I personally don't know the pricing if you choose that route, I imagine it's cheaper and more convenient than trying to track down physical copies of certain films.

First of all, don't pirate anything. There are only a couple that you could really justify pirating, but there's no reason to start with those. If you're truly interested and want to support Godzilla, pay for the movies.

A good starting point is the DVD The Godzilla Collection. It contains the following movies:

• Godzilla (1954)
  
• Godzilla Raids Again (1955)
  
• Mothra vs. Godzilla (1964)
  
• Ghidorah, the Three-Headed Monster (1964)
  
• Invasion of Astro-Monster (1965)
  
• All Monsters Attack (1969)
  
• Terror of Mechagodzilla (1975)
  
  In addition to the Japanese versions, all the U.S. edited cuts are included as well. However, I believe the original Godzilla is cropped to be widescreen, so if you want the original aspect ration, I suggest the Criterion release available on Blu-ray or DVD.
  
  A good place to start for some of the more recent movies is The Toho Godzilla Collection, Volumes 1 & 2. This set contains the following:
  
  
• Godzilla vs. King Ghidorah (1991)
  
• Godzilla vs. Mothra, aka Godzilla and Mothra: The Battle for Earth (1992)
  
• Godzilla vs. Mechagodzilla II (1993)
  
• Godzilla vs. SpaceGodzilla (1994)
  
• Godzilla vs. Destoroyah (1995)
  
• Rebirth of Mothra (1996)
  
• Rebirth of Mothra II (1997)
  
• Godzilla 2000: Millennium (1999)
  
• Godzilla vs. Megaguirus (2000)
  
• Godzilla, Mothra and King Ghidorah: Giant Monsters All-Out Attack (2001)
  
• Godzilla Against Mechagodzilla (2002)
  
• Godzilla: Tokyo S.O.S. (2003)
  
• Godzilla: Final Wars (2004)
  
  Full disclosure, I think this collection is only on DVD, but all of these movies are also available on Blu-ray in various singe- and multi-disc packs. But if you don't care about Blu-ray, this is a great set.
  
  This doesn't cover every Godzilla movie, but those two box sets are both pretty good ways to start, I think. If you have questions about specific movies or anything else let me know.

You could get him something like this Toho Godzilla Collection it comes with about 13 movies at a pretty decent price range. Or since he grew up watching them he probably watched some of the Showa movies so you could pre order the Showa Godzilla Criterion set that has every Godzilla film from 1954-1975. Or you could also buy Godzilla: King of the Monsters which comes out on the 27th this month.

https://www.amazon.com/dp/B00IQAUO5C/ref=cm_sw_r_cp_taa_7m5tDbFJKD0CA
You mean like one's like this?

Also found this, https://www.amazon.com/dp/B01JZKXCO6/ref=cm_sw_r_cp_taa_as5tDb43KBK7S

Is it worth it?

There's a couple of things: I've seen colorized versions of the original movies and they would colorize him green.

Scroll about halfway down the article to the picture of a green GodZilla with the caption 'The original Godzilla. TOHO'
https://www.google.com/amp/www.wsj.com/amp/articles/godzilla-was-a-very-different-beast-60-years-ago-1414666269

Or the Toho DVD collection: https://www.amazon.com/ToHo-Godzilla-Collection-Volumes/dp/B01JZKXCO6 He is green on the cover.

He is basically a giant lizard and your brain wants him to be green in the old black and white movies. Even in the later ones, his gray suit has a slight green tint to it. Or, in the 1998 film that ALOT of people are familiar with, he is green. 2000 obviously came after 1998, so Toho was trying to capitalize on that.

I'm just saying, sometimes he is green and sometimes he isn't. More people are more familiar with the Americanized versions of him and that's why more people remember him green.