Title says it all. But here's a thousand more words just to say it more elaborately. Everything from Sega is way more fun as a retro gamer to collect for than any other game company. It's true, and if you don't already agree, or if you do and you just need to hear someone else corroborate your opinion, then here's why:
What do retro game collectors like to collect? Whatever's plentiful, pretty much. The more obscure or notable, the better. What did Sega produce all of its life? Tons of shit. Consoles, add-ons, accessories, games... Just a buttload of everything they could think of, all of it interesting in some way.
Sega embraced the cutting edge. This started with the arcades, particularly in the late 80s with games like Hang-On and Out Run, which not only used state-of-the-art sprite-scaling hardware but featured super-sized cabinet systems with ridable vehicles that moved and interacted with the game. Later when it came to 3D, they scaled multi-million dollar aerospace simulator parts down to consumer-level arcade systems, and eventually the Sega Saturn. They were among the first fully-featured 3D consumer graphics in the industry. Unquestionably Sega was always on the cusp of innovation.
When it came to the console market, this meant they were always trying to one-up their competition. The first Sega console to make it outside of Japan, the Sega Master System, featured a number of add-ons, including one that allowed for 3D active-shudder technology on CRT-based TVs, something only just now being reintroduced. In Japan, the Master System was suped-up with the 3D feature built in, and easily upgraded sound that allowed for sophisticated MIDI sequences more akin to the Genesis than its 8-bit brethren. All model one Sega Master systems regardless of region had access to a secondary game media in the form of ROM cards. These were very similar in appearance to TurboGraphix-16's HuCards that would appear a few years later.
The Genesis is of course the most infamous for add-ons and accessories. Most variants of the system are fully back-compatible with Sega Master System games, but in an odd decision, the cartridge slot won't fit them. You had to buy the Power Base Converter, which didn't work on model two Genesis systems; or the UK-exclusive Master System Converter II, which did work on the model two, but couldn't play Sega Cards, only cartridges.
Then there were the two most famous add-ons for the system, which this time pushed its capabilities forward. The Sega CD add-on wasn't the first time a game console could use CDs, but it was close to it. Despite adding a second processor and more memory, games were only slightly enhanced from vanilla Genesis games, with the only real innovation being some very limited FMV playback. It was considered during its development to expand the on-screen color capability of the system, but it was decided the additional cost (an estimated $50) would impair its success (see FAQ). Had this been included, it might have rendered the 32x add-on completely pointless.
The 32x was pretty much pointless anyway, with only 30-something games released for it and a lifespan of basically one year. It used some of the hardware that would later be put in the Saturn, but with extremely limited memory. It was intended to transition customers to the new platform and keep the Genesis going. Instead customers just ignored it and waited for the next generation, in many cases skipping over Sega entirely once news circulated of the PlayStation and Nintendo 64.
Then there were all the different hardware revisions. In NA, the Master System saw two major revisions, which in addition to the converters on the Genesis and Game Gear gives collectors four options for playing Master System cartridges.
The Genesis was particularly ridiculous. It saw three major revisions in NA (four if you count the officially licensed Firecore clone console), plus the CDX model which also played Sega CD games. Then there was the portable Nomad, and the JVC X'Eye, a licensed third-party Genesis console with the Sega CD hardware implemented. On top of that there was the Pioneer Laseractive System with modules called PACs that allowed for videogames, one of which played Genesis games (with CD games playable on the main system's disc tray). So for the most hardcore collectors out there, you could have up to eight official ways of playing Genesis cartridges. (UPDATE: I've just been informed that the makers of the Firecore console also made an officially licensed handheld called the Retrogen, making it the ninth Genesis cartridge player.) This is of course excluding unofficial retro consoles that use emulation hardware.
All these add-ons and revisions often cost consumers hundreds of dollars, but today almost all of them can be had fairly inexpensively. Few other companies provide so much hardware and sub-libraries of games, and tons of obscure stuff for totally accessible prices is a total win for collectors.
Then there's the Sega Saturn, an under-appreciated console that can be had for a really low price these days. It has several diamonds in the rough within its library, though granted many were available on the PlayStation or PC. The Dreamcast got a little more love from consumers, but it can be had for just as cheaply, and its game library is even better.
It's ironic that the thing that ultimately killed Sega, pouring tons of R&D and production/marketing money into an ill-fated train of excessive hardware introductions is the thing that makes them the most fun and interesting for collectors. There's possibly more demand for their defunct products now, when they're cheap, than there ever was when they were new. They're fun to talk about, they're fun to show people, and they're fun to research and buy.
My favorite is the Sega CDX, an extremely compact Genesis variant intended to be part home console, part portable Discman wannabe. It's hard to imagine how they thought there'd be demand for such a thing, especially coupled with its $400 asking price, but now it's a hot ticket item for collectors. It fits in almost any space, works with virtually everything made for the Genesis, and is an incredibly slick piece of hardware even by today's standards. Clone systems can barely compete with its convenience. It's a little on the pricier side than most Sega hardware, but at $150-170, it's a respectable deal, and a damn fine addition to a retro enthusiast's shelf.
Best part of it all is finding and appreciating all the stuff you never knew existed from Sega. The Sega CD actually has a number of great titles hidden amongst the FMV-ridden trash. Even the 32x has great ports of After Burner and Space Harrier, not to mention original titles like Knuckles Kaotix, Kolibri, and Tempo. Discovering these games and enjoying them helps you appreciate all the things Sega had to offer, without the stigma that consumers had during the 90s. In terms of diversity, value, and potential fun, no other game company comes close. It just took almost twenty years for people to see it.
