Thats cool, nice collection there. I am sure some of those are encroaching on IP though (e.g. Flying Megaman under the NES Roms).
I'm not sure where the line is on legality of homebrew games but for absolute safety and redistribution I am guessing it has to be original and no sprites artwork or likeness of copyrighted material included.
Reason I am interested is it somewhat justifies the use of emulation software and makes it easier to include in a commercial project I am considering in the future. Also, as a potential subsection of a future website that some people from this site are looking to make. It would be cool to list those games in a really slick way on a website for those creators...but they have to be as close to 100% legally safe as possible.
Interestingly, Nintendo states that the actual emulator software itself is illegal. In their own words "The emulator promotes the play of illegal ROMs, NOT authentic games"
.  Mileage varies depending on country I guess and that stance can be argued no doubt in terms of the emulator as a tool for piracy and the ROMs themselves.
However, an emulator can be deemed 100% legal if people create original works for it specifically and the emulator author isn't promoting it's use as a way to obtain copyrighted material. (I base this on talks in my previous job with various IP lawyers, PirateBay founders and the lawyers that represented them in court ...relating to torrents and personal media storage etc.).
1. More on Nintendo's stance on Emulators and redistribution fo ROMs can be found here: http://ap.nintendo.com/faq/#oop_not_pd