Nom: Unknown Reality
Why: for creating mass-hysteria at their booth, oodles and oodles o' ppl yelling for new copied disks

Right, if only to make wolf_ less lonely:

Nomination: Philips quitting MSX
Why: the end of the commercial MSX era in the Netherlands, and Western Europe for that matter.

Nomination: the release of fMSX
Why: the start of widespread attempts to emulate MSX on all kinds of platforms; released under a sort of open source license and the mother of many other emulators due to its portability

Nom: Cas Cremers
Why: winning that MCM compo as a wizzkid, and creating many respected games after that.

Nomination: the release of CJS MSX emulator/Virtual MSX (whichever came first)
Why: the first MSX emulator, and the real start of the emulation scene. After it came MSX4PC and a whole lot of other emulators, of which fMSX is in my opinion the only other one which can claim to have defined MSX emulation (hence its nomination)

Nom: SD-Snatcher
Why: according to many, the best RPG on MSX (or best GAME even)

Nomination: the release of Aleste 2
Why: the best vertical shoot'em up on MSX2 ever, graphics, sound and gameplay-wise, and if it weren't for Space Manbow (already nominated), it would be the best shoot'em up, period.

Nom: Designer and Designer plus
Why: I really think these apps deserve cult-status. In their time the MSX was a common school/educational computer, and it might in fact be these Designers that might've got attention from kids, with as result: their own MSX.

Nomination: the release of Lightning, by Starcracks and Micronics
Why: the first demo written in 100% machinecode that looked at a real attempt to write a decent demo with smooth scrolls and effects not seen before. Of course, many demos after it were much better and REALLY showed what MSX(2) was capable of, but what came before was pretty much pathetic (I'm sorry, that includes earlier Merlasoft and FAC demos; Merlasoft because they were inexplicably in screen 7, but he redeemed himself later, and FAC III because it was in Basic). Or, as the authors put it themselves: "the REAL anti-Commodore demo!"

Nom: SymbOS
Why: the first, and prolly only, sense making graphical -Windows'ish- OS for MSX

Name: the release of Nemesis (1)
Why: Konami's first megaROM, and probably the first one on MSX.

yes, definitely Lightning! Definitely!

Nom: Microcabin snaredrum (various prods, Xak, Fray etc.)
Why: Finally a snaredrum that doesn't sound cheap, it had us all longing for it

Nom: Microcabin's music in general
Why: introduction of a new FM-Pac sound, it sounded quite different compared to 'normal' FM games (or scene music for that matter), it's still unmatched!

Nom: the release of MB
Why: a relief after messing around FST's limits

wolf_, I suggest combining your previous two nominations [edit: the Microcabin ones, you managed to slip a post in between] into "the release of Xak 1", which makes it more of an event. And if you happen to be writing a tune, maybe you could call it "insomnia". ;-)